File readme for Standards for Digital Line Graphs (DLG) documentation in the stdlg subdirectory of the public directory -- 9/01/94 -- Standards for DLG documentation is divided into three parts; Part 1: General (one file) Part 2: Specifications (four files) Part 3: Attribute Coding (eleven files) The "binary" or "image" command permits file transfer of all types , whether ASCII, WordPerfect, direct access, or executable, before using the "get" command. The "dir " command provides information on the file sizes in bytes and the date the file was last updated. FILE DESCRIPTION readme The ASCII formated file you are now reading *.txt Documentation converted to ASCII format. *.wp5 Documentation in original WordPerfect format. *.ps Documentation converted to PostScript format. *.tif Image in Tagged Interchange File Format (TIFF) (Used for figures not contained within .asc text files) stpt1all Contents for the complete standard and Part 1: General, containing series description and data sources, content, and structure stpt2txt Part 2: Specifications, containing coordinate systems, cell size and file extent, error definition, data quality, and distribution formats stpt2-2a Part 2: Specifications Appendix A, containing standard DLG distribution format stpt2-2b Part 2: Specifications Appendix B, containing optional DLG distribution format stpt2-2c Part 2: Specifications Appendices C, D, and E, containing 1:2,000,000-scale graphic format, map projection parameters, and U.S. National Map Accuracy Standards stpt3-tc Part 3: Attribute Coding introductory pages, containing table of contents, lists of figures, tables, and pages stpt3-in Part 3: Attribute Coding sections containing objectives, symbol references, and coding structure (pp 3-1 through 3-14) stpt3-hp Part 3: Attribute Coding section entitled Hypsography (pp 3-15 through 3-25) stpt3-hy Part 3: Attribute Coding section entitled Hydrography (pp 3-26 through 3-67) stpt3-sc Part 3: Attribute Coding section entitled Vegetative Surface Cover (pp 3-68 through 3-73) stpt3-nv Part 3: Attribute Coding section entitled Non-Vegetative Features (pp 3-74 through 3-78) stpt3-bd Part 3: Attribute Coding section entitled Boundaries (pp 3-79 through 3-91) stpt3-sm Part 3: Attribute Coding section entitled Survey Control and Markers (pp 3-92 through 3-100) stpt3-tr Part 3: Attribute Coding section entitled Transportation (pp 3-101 through 3-152) stpt3-ms Part 3: Attribute Coding section entitled Manmade Features (pp 3-153 through 3-192) stpt3-pl Part 3: Attribute Coding section entitled U.S. Public Land Survey System (pp 3-193 through 3-247) fig2-2b Figure for example diagram on p. 2B-19 (Part 2, Appendix B) fig3-1 Figure 3-1 on p. 3-39 fig3-2 Figure 3-2 on p. 3-71 National Mapping Program Technical Instructions Part 2 Specifications Standards for Digital Line Graphs (Current version containing all changes through 3/1/94) Department of the Interior U.S. Geological Survey National Mapping Division CONTENTS Page 2. Specifications . . . . . . . . . . . . . . . . . . . . . 2-1 2.l Coordinate Systems . . . . . . . . . . . . . . . . . 2-l 2.2 Cell Size and File Extent . . . . . . . . . . . . . 2-3 2.3 Error Definition . . . . . . . . . . . . . . . . . . 2-5 2.3.l Blunders . . . . . . . . . . . . . . . . . . 2-5 2.3.2 Systematic Errors . . . . . . . . . . . . . . 2-5 2.3.3 Random Errors . . . . . . . . . . . . . . . . 2-6 2.3.4 Standard Error . . . . . . . . . . . . . . . 2-6 2.4 Data Quality . . . . . . . . . . . . . . . . . . . . 2-7 2.4.l Lineage . . . . . . . . . . . . . . . . . . . 2-7 2.4.2 Positional Accuracy . . . . . . . . . . . . . 2-7 2.4.3 Attribute Accuracy . . . . . . . . . . . . . 2-8 2.4.4 Edge Matching . . . . . . . . . . . . . . . . 2-8 2.4.5 Quality Control Flags . . . . . . . . . . . . 2-9 2.4.6 Logical Consistency . . . . . . . . . . . . . 2-ll 2.4.7 Completeness . . . . . . . . . . . . . . . . 2-ll 2.5 Distribution Formats . . . . . . . . . . . . . . . . 2-12 APPENDICES Appendix 2-A Standard DLG Distribution Format . . . . . . . 2A-l Appendix 2-B Optional DLG Distribution Format . . . . . . . 2B-l Appendix 2-C l:2,000,000-Scale Graphic DLG Format . . . . . 2C-l Appendix 2-D Map Projection Parameters . . . . . . . . . . . 2D-l Appendix 2-E U. S. National Map Accuracy Standards . . . . . 2E-l TABLES Table 2.l Comparison of Standard and Optional DLG Formats . . 2-12 2. SPECIFICATIONS Specifications for DLG data will be described by considering the following subject areas: coordinate systems, cell size and extent, error definition, data quality and distribution format. 2.l COORDINATE SYSTEMS The positional descriptions for DLG data elements are expressed in one of several coordinate systems, dependent upon the distribution format selected. The DLG data in the standard distribution format are encoded using an internal file coordinate system to minimize storage requirements. The characteristics of this system are as follows: o The coordinate system is Cartesian. o The origin (x=0, y=0) is at the center of the cell. Some older files will have their origin below and to the left of the lower left corner of the cell. o The x axis of the coordinate system is parallel to a theoretical straight line connecting the southwest and southeast corners of the cell, and the y axis is perpendicular to that line. o One unit is equal to 0.00l inch at map scale. o The coordinate domain is limited to the range - 32768 to +32767. The file header contains the parameters of a transformation which can be used to convert the internal file coordinates to the ground coordinate system in either Universal Transverse Mercator (UTM) for l:24,000- and l:l00,000-scale DLG's, or Albers Conical Equal Area for l:2,000,000-scale DLG's. The DLG data in the optional distribution format are expressed in the units of the respective ground coordinate systems; that is, meters in the UTM or Albers Conical Equal Area systems. The l:2,000,000-scale DLG data in the graphics distribution format are expressed in geographic coordinates (latitude and longitude). These values are expressed in degrees, minutes, and seconds. 2.2 CELL SIZE AND FILE EXTENT In general the large-scale DLG's are stored and distributed in standard cells of 7.5-minutes of latitude by 7.5-minutes of longitude. Non-standard quadrangles which have a neatline extended to accommodate overedge information, (e.g. along national boundaries or in coastal areas) are collected as multiple 7.5- minute units. Of the l:24,000-scale data collected from l5-minute quadrangles, the majority are digitized as four 7.5- minute units, and distributed in standard 7.5-minute cells. A few older data files, collected from l5-minute quadrangles, were digitized in single l5- minute units, and are distributed in this format. In Alaska, data digitized from l:24,000/l:25,000-scale source material are stored in cells varying from l0-minutes to l8- minutes of longitude, by 7.5-minutes of latitude, depending on the latitude of the cell. Alaskan data digitized from l:63,360-scale source material are stored in cells varying from 20-minutes to 36-minutes of longitude, by l5-minutes of latitude, depending on the latitude of the cell. The intermediate-scale DLG's, covering the contiguous United States and Hawaii, are to be distributed in groups of files that make up a 30- x 30-minute area of coverage, each grouping representing the east or west half of a l:l00,000-scale source map. Each 30-minute area consists of a varying number of DLG files depending on the category and the feature density. The normal distribution group will be four l5-minute files per 30- minute area. If the feature density of an area is such that the file size would exceed the limitations of the processing software, then that 30-minute area would be covered by sixteen 7.5-minute files. In l986 the U.S. Geological Survey released a preliminary version of l:l00,000-scale DLG's. These data were packaged differently than described above. The distribution cells for the "roads and trails" portion of the "transportation" overlay, and for the "hydrography" overlay, consist of sixteen 7.5- minute files. The "railroads" and "miscellaneous transportation" portions of the "transportation" overlay consist of single 30-minute files. In northern Florida and southern Georgia, the "railroads" and "miscellaneous transportation" data may be in sixteen 7.5-minute files. The small-scale DLG's are distributed predominantly in multistate cells, which approximate the National Atlas sectional maps. The total number of l:2,000,000-scale DLG cells is twenty-one; fifteen for the conterminous United States, five for Alaska and one for Hawaii. The data for each cell are encoded in multiple thematic categories. Normally, there is one file per category. However, due to software limitations at the time of digitizing, some categories with a large number of elements may be encoded in several files. 2.3 ERROR DEFINITION DLG data may contain errors of three types: blunders, which should be removed prior to entry to the data base; systematic errors, occurring in a system-specific or a procedure-specific pattern; and accidental errors, which are of a purely random nature and are completely unpredictable. Although all three types may be reduced in magnitude by refinements in technique and precision, they never can be completely eliminated. 2.3.l Blunders For DLG data, a blunder is an error of major proportions often exceeding 0.009 inch (3 times the standard error) in the x or y component directions. This is the maximum error permitted for DLG data, and as such is easily identifiable. Moreover, a blunder is an indication that the data collection process has deteriorated beyond the level of simple systematic or random errors. Every effort is made to eliminate identifiable blunders during processing and quality-control operations. However, despite design precautions, some blunders may remain. 2.3.2 Systematic Errors Systematic errors are those errors that are introduced by procedures or systems and typically are predictable but not easily correctable. These types of errors cause a bias or artifact in the final product, but are generally not large enough to be classed as blunders. For DLG data, localized systematic errors could include artifacts which are typical of raster-digitized data. Unidentified and uncorrected systematic errors are included in and contaminate the accuracy statistics used to describe the final DLG. 2.3.3 Random Errors Random errors are those errors considered to be observational in nature or a result of limitations in measuring precision. They are caused by both system and human limitations. Random errors generally conform to a normal error distribution. 2.3.4 Standard Error The standard error statistic is used to describe the horizontal accuracy of a DLG, encompassing both random and systematic errors introduced during production of the data. The standard error is computed in both x and y component directions. Standard error (SE) for the x or y direction is defined as: where Si = DLG x or y coordinate of a test point St = true x or y coordinate of a test point n = number of test points The term St, "true" coordinate, refers to the "most probable" coordinate value, since values are normally derived from production map sources. Accuracy is computed by comparison of the DLG coordinate with true coordinates derived with a higher order of accuracy. Test points should be well defined and well distributed and have "true" coordinates with accuracies greater then the DLG accuracy criteria. 2.4 DATA QUALITY Five characteristics relating to digital data quality are included as sections of a quality report. The goal of this type of standard is to allow the user the freedom to evaluate the usefulness of the data for a given application, rather than applying a quantitative threshold towards each characteristic. The quality of Digital Line Graph data can be described in terms of the following five characteristics: lineage, positional accuracy, attribute accuracy, logical consistency, and completeness. The procedures for specifying and validating these characteristics are described in Part 5: Quality Control and Verification. 2.4.l Lineage Lineage data generally provide information on the source of the data file, collection procedures, processing steps, reference systems, projection transformation parameters, data resolution, and coordinate domain. DLG data carry some lineage information in the header record for each file. Format specifications designate specific fields for lineage data elements (see Appendices 2-A and 2-B). Additionally, lineage data is described in related NMD Technical Instructions, such as Procedure Manuals and Data Users Guides. 2.4.2 Positional Accuracy DLG positional accuracy is based on the use of standard USGS graphic products as the fundamental source for initial loading of the NDCDB. These source graphics are normally compiled to meet National Map Accuracy Standards (see Appendix 2-E), where 90 percent of well- defined features are to be within 0.02 inches of true mapped ground position. The DLG positional error shall be less than or equal to 0.003 inches standard error in both the x and y component directions, relative to the source that was digitized. Positional consistency of DLG elements that span quadrangle edges may be altered using edge alignment routines that result in "snapping" together corresponding node and line elements that are located within 0.020 inches of each other. The maximum positional adjustment for any node and associated line element would be 0.010 inches. 2.4.3 Attribute Accuracy DLG data represent the source graphic and, therefore, data for a given category will contain attribute codes that reflect the information portrayed on the source. All attribute codes of DLG data in the NDCDB will agree within 98.5 percent to attribute codes as described in Part 3 of this Standard: Attribute Coding. 2.4.4 Edge Matching Validation software provides for checking the edges of each quadrangle against the edges of the four adjacent quadrangles. Each edge of a DLG-3 is checked for positional and attribute matching along the neatlines of the adjoining DLG-3 cells, providing that the surrounding data cells are available at the time the DLG-3 is entered into the NDCDB. DLG's archived prior to implementation of edge matching requirements may not have been edge checked. All projects authorized after April 30, l988 are required to meet current edge matching specifications, both for joins internal to the project and for joins to adjacent DLG's already existing in the NDCDB. l00K DLG data archived prior to implementation of edge matching requirements are to be reworked to conform to current edge matching specifications. 2.4.5 Quality Control Flags Information in the header of the DLG-3 indicates the status of the file with respect to the edge matching described above. The four status flags contain the status of the West, North, East, and South edges of a DLG-3 as compared to the edges of the four adjoining DLG-3 files. Each of the four flags is followed by a status reason code that explains the status of the four edges respectively. The possible status values for a DLG-3 entered into the NDCDB are: (blank) = no reason code set, ("unchecked" for some earlier data sets) 0 = passed edge match check l = alignment discontinuity 2 = attribute discontinuity 3 = attribute and alignment discontinuity The possible reason codes are: (blank) = no reason code set, ("unchecked" for some earlier data sets) 4 = adjacent data do not exist 5 = adjacent data unavailable 6 = graphic discontinuity 7 = mismatch valid 8 = paneling unauthorized The following combinations of status flags and reason flags are currently valid for the processing software. blank, blank blank, 4 blank, 5 blank,8 0,blank l,6 l,7 2,6 2,7 3,6 3,7 The following is a brief explanation of the reason flags. 4 = adjacent data do not exist This flag is used with a status flag of blank (unchecked). This combination exists primarily for file edges which are adjacent to areas unmapped within the series/scale of products being digitized, e.g. coastal and international boundary locations. This flag is also used for U.S. Public Land Survey System (PLSS) file edges which border areas of the country not having PLSS information. 5 = adjacent data unavailable This flag is used with a status flag of blank (unchecked). It is appropriate for edges adjacent to areas having similar source material and data categories, but which have not been digitized and archived. A reason code with the value of 5 may be reset as the adjoining data cell becomes available for edge match verification. 6 = graphic discontinuity This flag indicates a discontinuity in classification or alignment between features on adjacent graphics which were digitized as represented. 7 = mismatch valid This reason flag applies in the case of a linear graph element ending precisely on the neatline or having a reasonable attribute value change as it crosses the neatline. (e.g. A road changing from third to fourth class at the neatline.) 8 = paneling unauthorized This flag is used with the edge status flag of blank and indicates that no authorization was in place for edge matching at the time the data were archived. In the course of checking and aligning an edge it is possible to encounter more than one reason for a mismatch status, such as both valid and graphic discontinuities. In such cases the reason flag is to be set to indicate the "worst case", i.e. the reason indicating the most serious problem with the edge and which in most cases would require some degree of correction in the future. For the above example, the graphic discontinuity reason flag would be set in preference to the mismatch valid flag. 2.4.6 Logical Consistency Logical consistency describes topological fidelity internal to a file. Certain node-area-line relationships are collected or generated to satisfy topological requirements. Some of these requirements include: lines begin and end at nodes, lines connect to each other at nodes, lines do not extend through nodes, left and right areas are defined for each line element and are consistent throughout the files and the lines representing the limits of the file (neatline) are free of gaps. 2.4.7 Completeness Completeness refers to the subset of features or objects represented in the DLG in relation to the domain, which is the source graphic. The DLG for a given category of data will contain at least the same level of content and detail shown on the source graphic. 2.5 DISTRIBUTION FORMATS Digital Line Graph data are available in two distribution formats: (l) standard and (2) optional. DLG's from l:2,000,000-scale maps are also available in a "graphics" format. The standard distribution format reflects design decisions intended to minimize storage requirements. Explicit topological linkages are contained only in the line elements (starting node, ending node, an area to the left of direction of travel, and an area to the right of the direction of travel). The optional distribution format was designed to facilitate data usage. The topological relationships explicitly encoded include starting node, ending node, area to the left of direction of travel, and area to the right of the direction of travel for line elements, bounding lines for area elements, and bounded lines for node elements. These files are typically larger than those in the standard format but, for certain applications, can simplify processing requirements. For example, because topological linkages are explicitly encoded for all line, node, and area elements, a polygon data structure can be easily created. These linkages facilitate Geographic Information System (GIS) applications of DLG data as well as generation of graphic products. The characteristics of the standard and optional DLG distribution formats are compared in table 2.l. The format and record contents for the standard and optional formats are summarized in Appendices 2-A an 2-B, respectively. Table 2-1 Comparison of DLG standard, optional and graphics formats þÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄþ Standard Optional Graphics þÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄþ Character set ASCII ASCII ASCII Logical record 144 bytes 80 bytes 20 bytes length Physical record Variable in Variable in Variable in length multiples multiples multiples (block size) of l44 bytes of 80 bytes of 20 bytes Coordinate system Internal file Ground planimetric: Geographic (thousandths of UTM-24K and lOOK, (latitude a map inch) Albers Conical and Equal Area-2M longitude) Topological Contained only Contained in node, None (only linkages in line elements area, and line contains elements line elements) þÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄþ The l:2,000,000-scale graphics distribution format was designed for use with the GS-CAM plotting package. GS- CAM is a modified version of the Cartographic Automatic Mapping (CAM) computer program. A graphic format file is organized by feature type, contains only minimal descriptive information about each line, and the relationship between lines is unspecified. These files are not topologically structured and contain no node or area elements. The format and record content for the l:2,000,000-scale graphics format is summarized in Appendix 2-C. Appendix 2-B Optional DLG Distribution Format In the optional DLG distribution format, topological linkages can be explicitly encoded for node and area elements as well as for line elements. The files are physically comprised of ASCII characters organized into fixed-length logical records of 80 characters (bytes). Bytes 1-72 of each record contain DLG data, and bytes 73-80 may be blank or contain a record sequence number. The record types used in the optional DLG distribution format may be categorized as header and data records. The following are considered header records: o File identification and description records (variable record formats) o Accuracy/miscellaneous records (not currently used) o Control-point identification records o Data-category identification records The following are considered data records: o Node and area identification records o Node-to-area linkage records* o Node-to-line linkage records o Area-to-line linkage records o Area-to-node linkage records* o Line identification records o Coordinate string records (lines) o Coordinate string records (areas)* o Attribute code records o Text records (not currently used) *Data distributed in optional format from the NDCDB will not contain these data records. The actual sequence of records in an optional distribution format DLG file is as follows: 1. Header records Ten file identification and description records Accuracy records (not currently used) Control point identification records (one per control point) Data category identification records (one per data category in the file) 2. Data records Node identification record Node-to-area linkage record(s)* Repeated Node-to-line linkage record(s) for each Attribute code record(s) node within a Text record(s) data category Area identification record Area-to-node linkage record(s)* Repeated Area-to-line linkage record(s) for each Coordinate string record(s)* area within a Attribute code record(s) data category Text record(s) Line identification record Repeated Coordinate string record(s) for each Attribute code record(s) line within a Text record(s) data category *Data distributed in optional format from the NDCDB will not contain these records. Descriptions of the contents of the various types of records in an optional distribution format DLG are contained in the following tables. ______________________________________________________________________________ ______________________________________________ FILE IDENTIFICATION AND DESCRIPTION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte* Comment ______________________________________________________________________________ ______________________________________________ 1 1 Banner ALPHA A72 1 72 " *** DLG-OPTIONAL FORMAT PRODUCED BY USGS PROSYS RELEASE x.x.x *** " 2 1 Name of digital ALPHA A40 1 40 The name of the digital data cartographic unit cell followed by the State two-character designators, separated by hyphens. --- --- Filler --- -- 41 41 1 space 2 2 Date of original ALPHA A10 42 51 Year of original source source material material followed by latest revision date if applicable; for example, 1956, 1965. 2 3 Date qualifier ALPHA A1 52 52 Qualifier to discriminate revision date if present. (P=photorevision, I=photo- inspection, L=limited revision, D=digital revision). 2 4 Scale of original INTEGER*4 I8 53 60 Scale denominator of source source material material; for example, 24000, 100000, or 2000000. (Record 2, data element 5 and Record 3, data elements 1 through 18 apply to 24K and 100K data files only. These fields contain filler in 2M data files.) --- --- Filler --- --- 61 63 3 spaces *The logical record length for the optional distribution format is 80 bytes, with 8 spaces of blank fill in bytes 73-80 of each record which may be used for a record sequence number. ______________________________________________________________________________ ______________________________________________ FILE IDENTIFICATION AND DESCRIPTION RECORDS-continued ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 2 5 Sectional indicator ALPHA --- 64 66 Codes S, F, or T for (100K files) size of section, plus sequence number. --- --- Filler --- --- 67 72 6 spaces --- --- Filler --- --- 1 41 41 spaces 3 1 Largest primary ALPHA A4 42 45 Largest primary contour contour interval interval, followed by the interval unit (1=feet, 2=meters). Present only if two or more primary intervals exist. (selected categories) 3 2 Comma ALPHA A1 46 46 comma separator 3 3 Largest primary ALPHA A4 47 50 Largest primary bathy- bathymetric contour metric interval, followed interval by the interval unit (1=feet, 2=meters, 3=fathoms). Present only if two or more primary intervals exist. (selected categories) --- --- Filler --- -- 51 51 1 space ______________________________________________________________________________ ______________________________________________ FILE IDENTIFICATION AND DESCRIPTION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 3 4 Smallest primary ALPHA A4 52 55 Smallest or only primary contour interval contour interval, followed by the interval unit as described above (selected categories). 3 5 Comma ALPHA A1 56 56 comma separator 3 6 Smallest primary ALPHA A4 57 60 Smallest or only primary bathymetric contour bathymetric contour interval, interval followed by the interval unit as described above (selected categories). 3 7-9 Coded Flags ALPHA A1 61 63 3 flags for future use 3 10 Coded Flag ALPHA A1 64 64 Database coded edge flag for internal NMD use. 3 11 EDGEWS ALPHA A1 65 65 Status flag for west edge, values are: b=unchecked, 0=passed, 1=alignment discontinuity, 2=attribute discontinuity, 3=attribute and alignment discontinuity. 3 12 EDGEWR ALPHA A1 66 66 Reason for EDGEWS, values are: b=no problem, 4= adjacent data do not exist, 5=adjacent data unavailable, 6=graphic discontinuity, 7=graphic mismatch valid, 8=paneling unauthorized. ______________________________________________________________________________ ______________________________________________ FILE IDENTIFICATION AND DESCRIPTION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 3 13 EDGENS ALPHA A1 67 67 Status flag for north edge, values are b,0,1,2, or 3 as above. 3 14 EDGENR ALPHA A1 68 68 Reason for EDGENS, values are b,4,5,6,7 or 8 as above. 3 15 EDGEES ALPHA A1 69 69 Status flag for east edge, values are b,0,1,2, or 3 as above. 3 16 EDGEER ALPHA A1 70 70 Reason for EDGEES, values are b,4,5,6,7 or 8 as above. 3 17 EDGESS ALPHA A1 71 71 Status flag for south edge, values are b,0,1,2, or 3 as above. 3 18 EDGESR ALPHA A1 72 72 Reason for EDGESS, values are b,4,5,6,7 or 8 as above. 4 1 DLG level code INTEGER*2 I6 1 6 * Code=3, DLG-3 4 2 Code defining ground INTEGER*2 I6 7 12 * 1Code=1 UTM (24K and 100K), planimetric reference Code=3 Albers Conical Equal system Area (2M files) 4 3 Code defining zone in INTEGER*2 I6 13 18 * 1Code for appropriate UTM ground planimetric zone (24K or 100K files), reference system Code=9999 for 2M files 1See General Purpose Transformation Package software documentation for additional information. * Listed values reflect current NMD standard. ______________________________________________________________________________ ______________________________________________ FILE IDENTIFICATION AND DESCRIPTION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 4 4 Code defining units INTEGER*2 I6 19 24 * 1Code=2, meters of measure for ground planimetric coordinates throughout the file 4 5 Resolution REAL*4 D18.11 25 42 The true ground distance corresponding to 0.001 inch at map scale. Scale Resolutions 1:24,000 0.61 M 1:25,000 0.635 M 1:48,000 1.22 M 1:62,500 1.587 M 1:63,360 1.61 M 1:100,000 2.54 M 1:250,000 6.35 M 1:2,000,000 50.80 M 4 6 Number of file-to- INTEGER*2 I6 43 48 number=4 map transformation parameters 4 7 Number of accuracy/ INTEGER*2 I6 49 54 Currently=0, none included miscellaneous records 4 8 Number (n) of INTEGER*2 I6 55 60 n=4 These points are control points usually, but not always, a definition of the file coverage. 1See General Purpose Transformation Package software documentation for additional information. * Listed values reflect current NMD standard. ______________________________________________________________________________ ______________________________________________ FILE IDENTIFICATION AND DESCRIPTION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 4 9 Number (q) of categories INTEGER*2 I6 61 66 * q=1 in the DLG file 4 10 Horizontal Datum INTEGER*2 I3 67 69 Horizontal Datum of DLG 'b' or 0 = NAD 27 1 = NAD 83 2 = Puerto Rico 3 = Old Hawaiian 4 = Local (Astro) 4 11 Vertical Datum INTEGER*2 I3 70 72 Vertical Datum of DLG 'b' or 0 = NGVD 29 1 = NAVD 88 2 = Local Mean Sea Level 5-9 1 Projection parameters REAL*8 3D24.15 1 72 Three parameters on each of for map transformation 5 records (see Appendix 2-4). 10 1 Internal file-to- REAL*4 4D18.11 1 72 X, Y coordinates resulting map projection from this transformation will transformation be expressed in the appro- parameters priate ground planimetric coordinate system. If the x, y coordinates are already in the ground coordinate system, the projection para- meters will be: A1=1.0, A2=0.0, A3=0.0, and A4=0.0. * Listed values reflect current NMD standard. ______________________________________________________________________________ ______________________________________________ CONTROL POINT IDENTIFICATION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 1-n 1 Control-point label ALPHA A6 1 6 "SW," "NW," "NE," or "SE" for four quadrangle corners. Field is padded with trailing blanks. 2 Latitude REAL*4 F12.6 7 18 In degrees and decimal degrees. 3 Longitude REAL*4 F12.6 19 30 In degrees and decimal degrees. Filler 31 36 6 spaces 4 X coordinate REAL*4 F12.2 37 48 In units in the appropriate zone of the ground plani- metric coordinate system. 5 Y coordinate REAL*4 F12.2 49 60 In units in the appropriate zone of the ground plani- metric coordinate system. --- --- Filler --- --- 61 72 12 spaces ______________________________________________________________________________ ______________________________________________ DATA CATEGORY IDENTIFICATION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 1-q 1 Category name ALPHA A20 1 20 The first 4 characters are unique to USGS/NMD data. 2 Attribute format codes INTEGER*2 I4 21 24 Blank or zero (0) indicates default (2I6) attribute formatting in major-minor pairs. 3 Highest node INTEGER*2 I6 25 30 Number of nodes referenced identification number. in the file. 4 Actual number of INTEGER*2 I6 31 36 Only if the DCF is not nodes in file packed, and the element ID numbers not compressed, will this number be dif- ferent from data element 3. --- Filler --- --- 37 37 1 space 5 Presence of node-to- INTEGER*2 I1 38 38 *0=node-area list not area linkage records included, 1=node-area list included. 6 Presence of node-to- INTEGER*2 I1 39 39 0=node-line list not line linkage records included, *1=node-line list included. --- Filler --- --- 40 40 1 zero or space ______________________________________________________________________________ ______________________________________________ * Values marked are values from data distributed from the NDCDB. ______________________________________________________________________________ ______________________________________________ DATA CATEGORY IDENTIFICATION RECORDS--continued ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 1-q 7 Highest area ID INTEGER*2 I6 41 46 Number of areas refer- number. enced in the file. 8 Actual number of areas INTEGER*2 I6 47 52 Only if the DCF is not in file packed, and the element ID numbers not compressed, will this number be different from data element 7. --- Filler --- --- 53 53 1 space 9 Presence of area-to- INTEGER*2 I1 54 54 *0=area-node list not node linkage records included, 1=area-node list included. 10 Presence of area-to- INTEGER*2 I1 55 55 0=area-line list not line linkage records included, *1=area-line list included. 11 Presence of area- INTEGER*2 I1 56 56 *0=area coordinates not coordinate lists included, 1=area coordinates included 12 Highest line INTEGER*2 I6 57 62 Number of lines identification number referenced in the file. ______________________________________________________________________________ ______________________________________________ * Values marked are values for data distributed from the NDCDB. ______________________________________________________________________________ ______________________________________________ DATA CATEGORY IDENTIFICATION RECORDS--continued ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 1-q 13 Actual number of INTEGER*2 I6 63 68 Only if the DCF is not lines in file packed, and the element ID numbers not compressed, will this number be different from data element 12. --- Filler --- --- 69 71 3 spaces 14 Presence of line- INTEGER*2 I1 72 72 0=line coordinates not coordinate lists included, *1=line coordinate list included. ______________________________________________________________________________ ______________________________________________ * Values marked are values for data distributed from the NDCDB. ______________________________________________________________________________ ______________________________________________ NODE AND AREA IDENTIFICATION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 1 Record type ALPHA A1 1 1 "N" or "A" 2 Element internal INTEGER*2 I5 2 6 Number is positive and seq- ID number uential from 1-n within each element type, where n is the highest element ID number. 3 Coordinates of node REAL*4 2F12.2 7 30 The area point is usually, point or representative but not always within the point for area polygon it represents. 4 Number of elements in INTEGER*2 I6 31 36 an area list (for nodes), or a node list (for areas) 5 Number of elements in INTEGER*2 I6 37 42 Number of line segments that line list intersect at the node or, for areas, line segments plus number of islands. 6 Number of x,y or INTEGER*2 I6 43 48 For area records only, lat-long points in blank for node records. area-coordinate list 7 Number of attribute INTEGER*2 I6 49 54 code pairs listed 8 Number of text INTEGER*2 I6 55 60 Zero (0). There are no characters listed text attributes for DLG data. 9 Number of islands INTEGER*2 I6 61 66 For area records only, blank within area for node records. --- --- Filler --- --- 67 72 6 spaces NODE-TO-AREA LINKAGE RECORDS FORTRAN FORMAT (12I6), for each node: The list consists of area internal ID numbers (which appear in bytes 2-6 of the area identification records) of all the areas that are adjacent to that node. There is no logical order to the list. NODE-TO-LINE LINKAGE RECORDS FORTRAN FORMAT (12I6), for each node: The list consists of line internal ID numbers (which appear in bytes 2-6 of the line identification records) of all the lines that connect to that node. The lines that begin at this node are included in the list as positive ID numbers. The lines which terminate at this node are included as negative ID numbers. There is no logical order to the list. AREA-TO-NODE LINKAGE RECORDS FORTRAN FORMAT (12I6) for each area: The list consists of node internal ID numbers (which appear in bytes 2-6 of the node identification records) of all nodes that are adjacent to that area. For those areas with islands, the number zero, used as a delimiter, marking the beginning of each island sublist. The format of this list is the same as the Area-Line list below. AREA-TO-LINE LINKAGE RECORDS FORTRAN format (12I6), for each area: The list consists of line internal ID numbers (which appear in bytes 2-6 of the line identification records) of all lines that bound that area and lines which are adjacent to an area. For those areas with islands (indicated by bytes 61-66 of the area's first record), the number zero, used as a delimiter, marking the beginning of islands. Lines with this area to the right are included as positive ID numbers. Lines with this area to the left are included as negative ID numbers. The list is ordered clockwise around the perimeter of the area and counterclockwise around each island, if any (counterclockwise around an island of an area is still a clockwise direction in reference to the area itself). The number zero is inserted in the list before each island sublist. Lines that do not contribute to the effective boundary of the area (those having both their area left and area right assigned to the same area) are not considered bounding lines. Therefore, these lines, while still present in the file, will not be referenced in the area-to-line linkage records. ______________________________________________________________________________ ______________________________________________ LINE IDENTIFICATION RECORDS ______________________________________________________________________________ ______________________________________________ Record Data Type Starting Ending Number Element Contents (Fortran Notation) Format Byte Byte Comment ______________________________________________________________________________ ______________________________________________ 1 Record type A1 1 1 "L" 2 Element internal ID number I5 2 6 Number is positive and seq- uential from 1-n within each element type, where n is the highest element ID number. 3 Starting node I6 7 12 Internal ID number. Refers to data element 2 of the node identification record. 4 Ending node I6 13 18 Internal ID number. Refers to data element 2 of the node identification record. 5 Left area I6 19 24 Internal ID number. Refers to data element 2 of the area identification record. 6 Right area I6 25 30 Internal ID number. Refers to data element 2 of the area identification record. --- Filler --- 31 42 12 spaces 7 Number of x,y coordinate I6 43 48 Number of coordinate pairs listed pairs listed. 8 Number of attribute I6 49 54 code pairs listed 9 Number of text characters listed I6 55 60 Zero (0). There are no text attributes for DLG data. LINE COORDINATE STRING RECORDS FORTRAN format (3(2F12.2)): The coordinates are in appropriate units in the designated ground planimetric coordinate system (usually meters in UTM), or in internal file units. CODE RECORDS As major-minor code attribute pairs, FORTRAN format (6(2I6)): Within each pair, the first integer is the major code and the second integer is the minor code. Each major and minor code is a one-to-four-digit integer, right justified within the six-byte field. AREA COORDINATE STRING RECORDS FORTRAN FORMAT (3(2F12.2)): The last data element in the area identification record contains the number of islands within the area. If this number is greater than zero, the following convention applies to the Area Coordinate list: The coordinates of the outside boundary of the area are listed first. The first coordinate of the outside boundary is repeated to signal the closure of this ring. Next, the coordinates of one of the islands are listed. The first coordinate of this boundary is repeated, again signaling the end of this ring. Next, the first coordinate of the outside boundary is listed as a ring delimiter. This process is repeated until the coordinates of the boundaries of all the islands are listed. The coordinates in this list are ordered so that the area being referenced is always to the right of the boundary described by the sequence of coordinates. Therefore, the list is ordered clockwise around the perimeter of the area and counterclockwise around each island, if any. The common coordinates between adjacent ring lines are only listed once, except for the beginning and ending of a ring. EXAMPLE 1: (A diagram illustrating this example may be found following the text.) Area line list (for area 41): 10, 11, -12, 0, 14, -15, 0, -18, 0, -82, -84, 21 Area node list (for area 41): 30, 31, 32, 0, 33, 34, 0, 35, 0, 36, 77, 76 Area coordinate list explanation: o Outside ring coordinates: (20, 50), (40, 60), (60, 50), (70, 40), (60, 20), (40, 10), (30, 10), (20, 30), (10, 40), (20, 50) starting point [ ( ] [ ) ] of outside ring L10 L11 L12 separate rings) o 1st island ring coordinates: (25, 45), (28, 39), (34, 43), (34, 48), (30, 50), (25, 45), (20, 50) ring closes first coordinate [ ( ] ) itself in outside ring L14 L15 delimiter o next island ring coordinates: (30, 30), (30, 20), (40, 20), (40, 30), (30, 30), (20, 50) ring delimiter [ ] L18 o last island ring coordinates: (50, 40), (50, 30), (48, 22), (58, 24) (60, 35), (55, 45), (50, 40), (20, 50) ring delimiter must be [ ( ] [ ) ] present at end of list if L82 L84 L21 islands are present. Note: Since lines 80, 85, and 86 have area 41 as both their area left and area right, they are not considered "boundaries" of area 41. Therefore, they are not used to build the area line list, area node list, or area coordinate list for this area. Complete area coordinate list: (20, 50), (40, 60), (60, 50), (70, 40), (60, 20), (40, 10), (30, 10), (20, 30), (10, 40), (20, 50), (25, 45), (28, 39), (34, 43), (34, 48), (30, 50), (25, 45), (20, 50), (30, 30), (30, 20), (40, 20), (40, 30), (30, 30), (20, 50), (50, 40), (50, 30), (48, 22), (58, 24), (60, 35), (55, 45), (50, 40), (20, 50) National Mapping Program Technical Instructions Part 3 Attribute Coding Standards for Digital Line Graphs (Current version containing all changes through 4/7/94) Department of the Interior U.S. Geological Survey National Mapping Division CONTENTS Page 3. Attribute Coding . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.1 Objectives. . . . . . . . . . . . . . . . . . . . . 3-1 3.2 Symbol References . . . . . . . . . . . . . . . . . 3-3 3.3 Coding Structure. . . . . . . . . . . . . . . . . . 3-4 3.3.1 Major Code Description . . . . . . . . . . . 3-6 3.3.2 Minor Code Description . . . . . . . . . . . 3-8 3.3.3 Common Attribute Codes . . . . . . . . . . .3-10 3.4 Hypsography--Major code 020 . . . . . . . . . . . .3-15 3.4.1 General Principles . . . . . . . . . . . . .3-15 3.4.2 Node Attribute Codes . . . . . . . . . . . .3-17 3.4.3 Area Attribute Codes . . . . . . . . . . . .3-17 3.4.4 Line Attribute Codes . . . . . . . . . . . .3-17 3.4.5 Single-Point Attribute Codes . . . . . . . .3-21 3.4.6 General Purpose Attribute Codes. . . . . . .3-22 3.4.7 Descriptive Attribute Codes. . . . . . . . .3-22 3.4.8 Parameter Attribute Codes. . . . . . . . . .3-24 3.5 Hydrography--Major Code 050 . . . . . . . . . . . .3-26 3.5.1 General Principles . . . . . . . . . . . . .3-26 3.5.2 Node Attribute Codes . . . . . . . . . . . .3-32 3.5.3 Area Attribute Codes . . . . . . . . . . . .3-34 3.5.4 Line Attribute Codes . . . . . . . . . . . .3-43 3.5.5 Single-Point Attribute Codes . . . . . . . .3-46 3.5.6 General Purpose Attribute Codes. . . . . . .3-48 3.5.7 Descriptive Attribute Codes. . . . . . . . .3-60 3.5.8 Parameter Attribute Codes. . . . . . . . . .3-65 3.6 Vegetative Surface Cover--Major Code 070. . . . . .3-68 3.6.1 General Principles . . . . . . . . . . . . .3-68 3.6.2 Node Attribute Codes . . . . . . . . . . . .3-69 3.6.3 Area Attribute Codes . . . . . . . . . . . .3-69 3.6.4 Line Attribute Codes . . . . . . . . . . . .3-72 3.6.5 Single-Point Attribute Codes . . . . . . . .3-73 3.6.6 General Purpose Attribute Codes . . . . . .3-73 3.6.7 Descriptive Attribute Codes . . . . . . . .3-73 3.6.8 Parameter Attribute Codes . . . . . . . . .3-73 3.7 Non-Vegetative Features--Major Code 080 . . . . . .3-74 3.7.1 General Principles . . . . . . . . . . . . .3-74 3.7.2 Node Attribute Codes . . . . . . . . . . . .3-75 3.7.3 Area Attribute Codes . . . . . . . . . . . .3-75 3.7.4 Line Attribute Codes . . . . . . . . . . . .3-77 3.7.5 Single-Point Attribute Codes . . . . . . . .3-77 3.7.6 General Purpose Attribute Codes . . . . . .3-78 3.7.7 Descriptive Attribute Codes . . . . . . . .3-78 3.7.8 Parameter Attribute Codes . . . . . . . . .3-78 3.8 Boundaries--Major Code 090. . . . . . . . . . . . .3-79 3.8.1 General Principles . . . . . . . . . . . . .3-79 3.8.2 Node Attribute Codes . . . . . . . . . . . .3-82 3.8.3 Area Attribute Codes . . . . . . . . . . . .3-83 3.8.4 Line Attribute Codes . . . . . . . . . . . .3-88 3.8.5 Single-Point Attribute Codes . . . . . . . .3-90 3.8.6 Parameter Attribute Codes. . . . . . . . . .3-90 3.9 Survey Control and Markers--Major Code 150. . . . .3-92 3.9.1 General Principles . . . . . . . . . . . . .3-92 3.9.2 Node Attribute Codes . . . . . . . . . . . .3-95 3.9.3 Area Attribute Codes . . . . . . . . . . . .3-95 3.9.4 Line Attribute Codes . . . . . . . . . . . .3-95 3.9.5 Single-Point Attribute Codes . . . . . . . .3-97 3.9.6 General Purpose Attribute Codes. . . . . . .3-99 3.9.7 Descriptive Attribute Codes. . . . . . . . .3-99 3.9.8 Parameter Attribute Codes. . . . . . . . . .3-99 3.10 Transportation--Major Codes 170, 180, 190 . . . . 3-101 3.10.1 General Principles . . . . . . . . . . . . 3-101 3.10.2 Instructions for the Use of Attribute Codes for Roads and Trails . . . . . . . . . . 3-111 3.10.3 Instructions for the Use of Attribute Codes for Railroads. . . . . . . . . . . . . . 3-133 3.10.4 Instructions for the Use of Attribute Codes for Pipelines, Transmission Lines, and Miscellaneous Transportation Features. . 3-143 3.11 Manmade Features--Major Code 200. . . . . . . . . 3-153 3.11.1 General Principles . . . . . . . . . . . . 3-153 3.11.2 Node Attribute Codes . . . . . . . . . . . 3-159 3.11.3 Area Attribute Codes . . . . . . . . . . . 3-159 3.11.4 Line Attribute Codes . . . . . . . . . . . 3-166 3.11.5 Single-Point Attribute Codes . . . . . . . 3-170 3.11.6 General Purpose Attribute Codes . . . . . 3-173 3.11.7 Descriptive Attribute Codes . . . . . . . 3-189 3.11.8 Parameter Attribute Codes. . . . . . . . . 3-192 3.12 U. S. Public Land Survey System--Major Code 300 . 3-193 3.12.1 Background . . . . . . . . . . . . . . . . 3-193 3.12.2 General Principles . . . . . . . . . . . . 3-194 3.12.3 Node Attribute Codes . . . . . . . . . . . 3-200 3.12.4 Area Attribute Codes . . . . . . . . . . . 3-208 3.12.5 Line Attribute Codes . . . . . . . . . . . 3-234 3.12.6 Single Point Attribute Codes . . . . . . . 3-239 3.12.7 Parameter Attribute Codes . . . . . . . . 3-239 3.12.8 Irregular Rectangular Surveys in Ohio & Indiana . . . . . . . . . . . . . . . . 3-241 FIGURES Figure Page 3-1 Attribute and parameter coding for hydrography coincident with vegetative surface cover . . . . . . .3-39 3-2 Attribute and parameter coding for woods, submerged woods, wooded swamp and submerged wooded swamp . . . .3-71 TABLES Table Page 3-1 Summary of attribute code changes . . . . . . . . . . . 3-5 3-2 Current major attribute codes . . . . . . . . . . . . . 3-7 3-3 Origins of the U.S. rectangular surveys . . . . . . . 3-211 3-3a Origins of U.S. private surveys in Ohio . . . . . . . 3-213 3-4 Township duplicates . . . . . . . . . . . . . . . . . 3-216 3-5 Named land grant codes. . . . . . . . . . . . . . . . 3-220 (Current version containing all changes through 11/15/93) 3.1 OBJECTIVES Digital cartographic data produced by the National Mapping Program are intended to support the requirements of a broad spectrum of users, not only for traditional cartographic products, but also for input to geographic information systems, for the production of graphics, and for automated spatial analyses. The data are collected in logical categories that comprise unique themes, not necessarily corresponding to traditional feature separates. Attribute codes, also called feature codes or classification attributes, are used to describe the physical and cultural characteristics of digital line graph (DLG) data elements: nodes, areas, and lines. Part 3 describes the general characteristics of the DLG coding scheme, defines the attribute codes used in each DLG data category, and provides guidance for the standardized application of these codes in the digitizing process. In the initial effort of building the DLG data base, the primary source materials used for data collection are published 1:24,000-, 1:25,000-, and 1:100,000-scale topographic maps. Field notes, aerial photographs, and compilation materials are not normally used directly. It is therefore necessary to prescribe the use of attribute codes based on information depicted on published maps. Every standard cartographic symbol will have an attribute code number, although there are situations where more than one attribute code will be required to fully describe a feature. The DLG file will reflect the level of detail or feature generalization of the source map. Therefore, many of the attribute codes are scale dependent and may not apply to a given source. Attribute codes are formulated according to the following guidelines: o Minimize redundant information. Generally, attribute codes are not assigned to a feature if they can be derived from relationships to adjacent features. For example, in the U.S. Public Land Survey System (PLSS) category, township extremity lines are not explicitly coded because this attribute can be derived by examining the attributes of the two areas that bound each line. o Provide sufficient reference information to support integration with large, multipurpose data bases. Many organizations maintain sets of mission-specific thematic or statistical data that are combined with cartographic base categories for both display and analysis. The DLG attribute coding scheme attempts to facilitate this process by the support of a variable number of attributes assigned to each feature, which creates an open-ended structure to which a user may add information, and by the use of established Federal Information Processing Standard (FIPS) codes, where available. o Describe the interrelations between cartographic elements. The interrelationships between cartographic elements are expressly encoded where appropriate. For example, the "right bank" and "left bank" of a river are designated rather than "bank" so that the direction of flow can be determined. A node is coded at the beginning of a single line stream for the same reason. 3.2 SYMBOL REFERENCES When an attribute code is specifically related to a standard cartographic symbol, the symbol number is cited. Symbol numbers refer to the following National Mapping Program Technical Instructions: (A) Standards for 1:24,000- and 1:25,000-Scale Quadrangle Maps, Part 6: "Publication Symbols (Supplement)" - December 1981. (B) Standards for 1:100,000-Scale Quadrangle Maps, Part 4: "Publication Symbols" - May 1984. (C) Standards for 1:24,000- and 1:25,000-Scale Quadrangle Maps, Part 5: "Publication Symbols" - May 1984. (D) Standards for Provisional Edition Maps, 1:24,000- and 1:25,000-Scale, Part 2: "Compilation Symbols" - January 1982. In reference A the symbol number is cited. In references B and C, the feature separate number and item number are attached to form a symbol number, for example, 145.2. In reference D, the section number and item number are attached to form a symbol number, for example, 2103.01. Throughout Part 3, each symbol number cited will have the reference letter in parentheses after it, for example, 207(A), 145.2(B), 512.61, 545.5 (C), or 2103.01(D). When a symbol has been eliminated from the Technical Instructions, it may be referred to as an "old" symbol, for example, old symbol 512.57(C). 3.3 CODING STRUCTURE Each attribute code identifies the general data category to which a feature belongs, as well as the specific nature of the feature. Codes also provide additional descriptive information. Many features are uniquely described by a single attribute code. Others may require two or more codes for a complete description. If multiple attributes are needed to describe a feature, their ordering is not significant, except in the case of highway route numbers. It is not necessary for each element to have associated attributes. A DLG attribute code is composed of two distinct numeric fields: a three digit major code, the first two digits of which identify the data category to which the feature belongs, and a four digit minor code, which specifically describes the feature. This document supersedes "Computer Files and Attribute Codes for Digital Line Graphs" (January 1980, revised February 1982) as well as National Mapping Program Data Users Guide 1, "Digital Line Graphs from 1:24,000-scale Maps" (1990), National Mapping Program Data Users Guide 2: "Digital Line Graphs from 1:100,000-scale Maps" (1989), and National Mapping Program "Digital Line Graph Attribute Coding Standards" (1985) in defining attribute codes to be used for DLG's. In this document, some data category names are changed. Also, some attribute codes replace previously defined codes, some are newly defined, and some are modified. All are explained in greater detail than in the previous documents. The changes are summarized in Table 3-1 by major code. In the categories where the major code was changed, the minor codes were changed. Table 3-1 Summary of attribute code changes Current Prior Category Type of Change major major code code 020 020 Hypsography Replacement of minor codes --- 030 Streams Included in 050 Hydrography --- 040 Water Bodies Included in 050 Hydrography --- 050 Wetlands Included in 050 Hydrography --- 060 Coastal Features Included in 050 Hydrography 050 --- Hydrography Newly defined 070 --- Vegetative Surface Cover Newly defined 080 --- Non-Vegetative Features Newly defined 090 090 Boundaries Expanded codes, definitions 150 --- Survey Control and Markers Newly defined 170 100 Roads and Trails Replacement 180 110 Railroads Replacement --- 120 Water Navigation Included in 050 Hydrography 190 130 Pipelines, Transmission Lines, and Miscellaneous Transportation Features Replacement 200 140 Manmade Features Replacement 300 --- U.S. Public Land Survey System (PLSS) Expanded codes, definitions 3.3.1 Major Code Description The first two digits of the major code uniquely identify the data category to which the described element belongs. Table 3-2 lists currently used major codes and the categories they represent. The third digit of the major code is used to designate the interpretation of the minor code in two ways: o if it is zero, the minor code numbers represent a description or classification of a specific feature, for example, 050 0300, which identifies a spring. o if it is not a zero, the minor code numbers have special interpretations as a parameter. The interpretation to be applied is given for each category. For example, 055 ---- is used to encode the value of a river mile mark. Table 3-2 Current major attribute codes Major code Base category 020 Hypsography 050 Hydrography 070 Vegetative Surface Cover 080 Non-Vegetative Features 090 Boundaries 150 Survey Control and Markers Transportation systems 170 Roads and Trails 180 Railroads 190 Pipelines, Transmission Lines, and Miscellaneous Transportation Features 200 Manmade Features Nonbase Category 300 U.S. Public Land Survey System 3.3.2 Minor Code Description The first digit of the minor code is normally zero. If it is not a zero, the number is used as a modifier to provide additional information about a feature. For example, code 302 0001 identifies township 1 north as a full township; but code 302 4002 identifies township 2 north as a half township in the PLSS. The remaining three digits are normally used to classify specific features. The type of element described by a particular code can be determined from the value of these digits: o node: 001 - 099 o area: 100 - 199 o line: 200 - 299 o single-point (degenerate line): 300 - 399 o general purpose codes (apply to multiple feature types): 400-499 o descriptive codes: 600-699 Exceptions to this scheme are discussed below as well as noted in the specific code descriptions. The general purpose codes are used on features that may be digitized as a node, area, or line depending on the size and position of the feature. The descriptive codes are used with another code to qualify its meaning. General purpose and descriptive attribute codes were added to the coding scheme in 1982. They are, therefore, not used in, or defined for, the two categories collected most heavily before 1982, U.S. Public Land Survey System and boundaries. The last three digits of the minor codes may also be used as a parameter code. Parameters are used when a minor code can legitimately assume a range of values, for example, water elevation or highway route number. The meaning of a parameter code is derived from the (non zero) third digit of the major code. Parameters are both category and feature specific. 3.3.3 Common Attribute Codes In general, the meaning of an attribute code is unique to the feature it describes. There are, however, several exceptions. Outside area (000 0000) Each DLG provides a coherent description of that portion of the earth's surface covered by a 1:24,000-scale, 7.5-minute cell, or a specific subdivision of another scale source. To maintain topological consistency and to facilitate the combination (integration) of multiple DLG's, the area outside the cell is specifically identified for each DLG. This area element, which must be the first area present in each data category, is assigned a single attribute code with major and minor codes both equal to zero. Photorevised features (XX0 0000) Map features obtained by photorevision methods are printed in purple on 1:24,000- and 1:25,000-scale maps. They are described by attribute codes from the appropriate category. In addition, a code consisting of major code XX0, where XX are the two digits uniquely identifying the data category, and a minor code of zero, will also be attached. The photorevised code can be applied to any feature types but can not be used alone except as a line code for a photorevised line in the Boundaries category. For example: a. A class 3 road added by photorevision would be coded as follows: 170 0000 - obtained by photorevision 170 0209 - improved light duty b. A boundary line added by photorevision would be coded as follows: 090 0000 - obtained by photorevision The photorevised code is not assigned to a node except when the node represents a photorevised feature on the map. For example, a lake or pond, 0.030 inch or less in diameter with a drain attached, added by photorevision is digitized as a node and coded as follows: 050 0000 - obtained by photorevision 050 0200 - shoreline 050 0421 - lake or pond This code may also be used in conjunction with the best estimate of position and (or) classification code, when map features obtained by photorevision methods are printed in purple on 1:24,000- and 1:25,000-scale maps but are not labeled. For example, a class 3 or 4 road that does not appear to be a part of the road network might be coded as follows: 200 0000 - obtained by photorevision 200 0214 - racetrack or drag strip 208 0000 - best estimate of position or classification Best estimate of position and (or) classification (XX8 0000) The attribute code consisting of major code XX8, where XX are the two digits uniquely identifying the data category, and a minor code of zero indicates that the position and (or) classification of the feature is not sufficiently clear to warrant unqualified use of the attribute code assigned. Coincident feature (XX9 00YY) The attribute code having major code XX9, where XX are the two digits uniquely identifying the data category, is used to indicate that the digitized feature occupies the same position as a feature from another data category. The second category is identified by the last two digits in the minor code. YY are the first two digits of the major code of the second category. For example: 309 0009 - land line coincident with boundary 099 0017 - boundary coincident with road 099 0002 - boundary coincident with watershed divide In most cases the lines where features are coincident are shown on the published map, however, land lines are omitted where they coincide with features of higher order symbolization, such as civil boundaries, roads, levees, or canals. These codes are included primarily as an aid in vertical integration of data from several categories. Specific instructions applicable to a given category of data appear in the code descriptions for that category. Processing line (XX0 0299) The attribute code consisting of major code XX0, where XX are the two digits uniquely identifying the category, and a minor code of 0299, indicates that a digitized line has segmented the data within a file for processing. For example: 050 0299 - Processing line code for hydrography This code is included primarily as an aid in the processing of large files that exceed the limitations of routines within the processing system (PROSYS). This sheet represents pages 3-13, which is blank (Current version containing all changes through 11/15/93) 3.5 HYDROGRAPHY--MAJOR CODE 050 3.5.1 General Principles The purpose in digitizing hydrography is to collect information about streams, bodies of water, wetlands, coastal water, and water used for transportation and related hydrographic features in a manner that permits the extraction and derivation of data to suit the needs of the data users. This information is not collected for specific hydrologic studies or for navigational assistance. One intention in collecting hydrography is to capture the direction of the flow by theoretically looking downstream and indicating right and left banks. Where the flow direction of a stream cannot be determined from the source material, the adjoining quadrangles are examined to obtain the information. If the directional flow still cannot be determined, the nodes and (or) banks are not coded to indicate flow. All double line streams are digitized as areas. Double line streams that join another double line stream or a water body are closed by an arbitrary closure line. The description of hydrographic features uses all of the types of codes: node, area, line, single-point, general purpose, and descriptive. All hydrographic features that have attribute codes assigned are assumed to be perennial unless the attribute code for "intermittent" is also assigned. Hydrographic features do not carry attribute codes for information that can be derived, such as intersections and junctions. This means that there will be unattributed nodes, areas, and lines. When an area feature, which can be identified by a code, is subdivided by linear features or closure lines, each resultant smaller area is identified by the appropriate code. The background land area is not assigned an attribute code. In some cases, land occurs as a brown area 0.030 inch in diameter or smaller. This is digitized as a degenerate line with the appropriate shoreline code. 3.5.1.1 Hydrography Attribute Codes The attribute codes used in digitizing hydrographic information are listed in this section. Instructions for the use of the attribute codes are given in sections 3.5.2 through 3.5.8. o Node attribute codes 050 0001 Upper origin of stream 050 0002 Upper origin of stream at water body 050 0003 Sink, channel no longer evident 050 0004 Stream entering water body 050 0005 Stream exiting water body o Area attribute codes 000 0000 Outside area 050 0100 Alkali flat 050 0101 Reservoir 050 0102 Covered reservoir 050 0103 Glacier or permanent snow field 050 0104 Salt Evaporator 050 0105 Inundation area 050 0106 Fish hatchery or farm 050 0107 Industrial water impoundment 050 0108 Area to be submerged 050 0109 Sewage disposal pond or filtration plant 050 0110 Tailings pond or settling basin 050 0111 Marsh, wetland, swamp, or bog 050 0112 Mangrove area 050 0113 Rice field 050 0114 Cranberry bog 050 0115 Flats (tidal, mud, sand, or gravel) 050 0116 Bays, estuaries, gulfs, oceans, or seas 050 0117 Shoal 050 0118 Soda evaporator 050 0119 Duck pond 050 0120 Void area 050 0121 Obstruction area in water area o Line attribute codes 050 0200 Shoreline 050 0201 Manmade shoreline 050 0202 Closure line 050 0203 Indefinite shoreline 050 0204 Apparent limit 050 0205 Outline of a Carolina bay 050 0206 Danger curve 050 0207 Apparent shoreline 050 0208 Sounding datum 050 0209 Low-water line 050 0299 Processing line o Single-point attribute codes (degenerate lines) 050 0300 Spring 050 0301 Nonflowing well 050 0302 Flowing well 050 0303 Riser 050 0304 Geyser 050 0305 Windmill 050 0306 Cistern o General purpose attribute codes (apply to nodes, areas, lines, or degenerate lines) 050 0400 Rapids 050 0401 Falls 050 0402 Gravel pit or quarry filled with water 050 0403 Gaging station 050 0404 Pumping station 050 0405 Water intake 050 0406 Dam or weir 050 0407 Canal lock or sluice gate 050 0408 Spillway 050 0409 Gate (flood, tidal, head, or check) 050 0410 Rock 050 0411 Crevasse 050 0412 Stream 050 0413 Braided stream 050 0414 Ditch or canal 050 0415 Aqueduct 050 0416 Flume 050 0417 Penstock 050 0418 Siphon 050 0419 Channel in water area 050 0420 Wash or ephemeral drain 050 0421 Lake or pond 050 0422 Coral reef 050 0423 Sand in open water 050 0424 Spoil area, dredged area, or dump area 050 0425 Fish ladders 050 0426 Holiday area o Descriptive attribute codes 050 0601 Underground 050 0602 Overpassing 050 0603 Elevated 050 0604 Tunnel 050 0605 Right bank 050 0606 Left bank 050 0607 Under construction 050 0608 Salt 050 0609 Unsurveyed 050 0610 Intermittent 050 0611 Abandoned or discontinued 050 0612 Submerged or sunken 050 0614 Dry 050 0615 Mineral or hot (sulphur, alkali, and so on) 050 0616 Navigable - transportation 050 0617 Underpassing 050 0618 Earthen construction 050 0619 Interpolated elevation 050 0621 - 0629 Decimal fractions of feet or meters o Parameter attribute codes 05N ---- Elevation of actual or interpolated water surface N = 1 for whole feet = 2 for whole meters = 6 for whole feet below datum = 7 for whole meters below datum Notes: a. Elevation value is flush right, four digits. b. To express elevations in decimal feet or meters, use the above parameter codes in conjunction with attribute codes 050 0621 through 050 0629. c. Elevations exceeding 9,999 feet must be expressed in meters. 055 ---- River mile, value in four spaces, flush right 050 0000 Photorevised feature 058 0000 Best estimate of classification or position 059 00-- Coincident feature 3.5.2 Node Attribute Codes The primary purpose of the node attribute codes is to assist in determining the direction of water flow. In assigning the node codes, the term "water body" refers to any areal feature digitized in the hydrography category. These codes apply to nodes found at the terminus of a given single-line stream segment. Nodes are not coded at connecting points where lines coded left and right bank intersect other left and right bank lines. Nodes are not coded where lines coded left and right bank connect lines bounding water bodies. Also nodes are not coded in places where direction of flow cannot be determined. 050 0001 Upper origin of stream This code identifies a node placed at the true beginning of a stream, where it is first shown. It is not used to mark stream junctures, even though the name of the stream changes, or to mark streams that exit from a water body. 050 0002 Upper origin of stream at water body This code identifies a node placed where a stream originates either within the limits of or at the point of exit from a water body. It is not used to identify any subsequent exits from water bodies further downstream. 050 0003 Sink A sink is the definite point where a stream flows underground, shown by symbols 407(A), 141.8(B), 541.12(C), or 2202.04(D). This code is used to identify a node placed at the point of disappearance. This code is not used to identify points where streams enter manmade features, such as aqueducts or siphons, or where streams enter and subsequently exit water bodies. 050 0004 Stream entering water body This code identifies a node placed at the terminus of a single-line stream segment where it ends within the limits of or at the perimeter of a water body. 050 0005 Stream exiting water body This code identifies a node placed at the terminus of a single-line stream segment where it begins within the limits of or at the perimeter of a water body, other than at an upper origin of a stream. 3.5.3 Area Attribute Codes 000 0000 Outside area This code is described in section 3.3.3. 050 0100 Alkali flat This code identifies a point placed within an area shown by symbols 450(A), 141.16(B), 541.28(C), or 2203.08(D) and labeled. 050 0101 Reservoir This code identifies an area point placed in a reservoir shown by symbols 179, 413 (A); 112.6, 141.12, 141.13, 145.2 (B); 512.61, 541.24 (C); or 2203.09(D) that is labeled or named as a reservoir. Use code 050 0200 for identification of natural shoreline around symbols 413, 141.12, 141.13, or 2203.09, and code 050 0201 for manmade shoreline around symbols 179 or 145.2. If the symbol is 0.030 inch or less in diameter, digitize as a degenerate line or node and add the shoreline code. This code is not used to identify features related to sewage treatment, fish farming, or water filtration. 050 0102 Covered reservoir This code identifies a point placed in a reservoir area shown by symbol 180(A); 512.62, 545.6 (C); or 2106.08(D) and named or labeled as a reservoir. If the symbol is 0.030 inch or less in diameter, digitize as a degenerate line or node and add the shoreline code. Use code 050 0201 for identification of manmade shoreline of this feature. This code does not apply to 1:100,000-scale maps. 050 0103 Glacier or snowfield This code identifies a point placed in an area depicted by symbols 428, 429, 430 (A); 141.27, 141.28 (B); 541.43 through 541.45 (C); or 2205.04(D). Because the symbols vary because of the contouring, which is not pertinent to the hydrographic category, the same code is applied to all three symbols. Any areas where the glacial moraine pattern overlaps a glacier is coded coincident with the Non-Vegetative Features category (059 0008). The outline of the area is not given an attribute code. 050 0104 Salt evaporator This code identifies the points placed in each section of areas shown by symbols 439(A), 141.15(B), 541.27(C), or 2205.10(D) and labeled. The pattern of ditches is digitized and coded (see code 050 0414). 050 0105 Inundation area This code identifies a point placed in the area of land between the normal operating level and the high water line in reservoirs or lakes impounded by dams. This area is shown by symbols 448(A), 141.38(B), 541.56 or 546.1 (C). Generally, code the outer line as symbolized. However, on older 1:24,000-scale quads, if the outer line is shown as an indefinite shoreline and the inundation area is in a non-coastal area, then code the outer line as intermittent shoreline (see code 050 0203 for further explanation). If an area subject to controlled inundation is symbolized with an elevation value on the shoreline defining the area, the elevation parameter code is added. Use code 050 0412 or 050 0414 for identification of drainage pattern in the area. 050 0106 Fish hatchery, fish farm, or fish pond This code identifies a point placed in any area shown by symbols 179(A); 112.6, 145.2 (B); 512.61, 545.5 (C); or 2205.11(D) and labeled. The label may vary to indicate the species or the controlling agency. The outline is coded 050 0201 if shown in black and 050 0200 if shown in blue. The major ditches are coded 050 0414 if shown in blue or 050 0201 if shown in black. The fish pond, unique to maps of Hawaii, may or may not be labeled. If the outline is shown by a solid black line, the outline is coded 050 0201; if shown by a dashed black line also use code 050 0611 (abandoned) for the area. In all cases, each section has a coded area point placed in it. 050 0107 Industrial water impoundment This code identifies a point placed in an area that is shown by symbols 410(A), 141.12(B), 541.23(C), or 2203.03(D), and carries a label that indicates the water is collected for industrial use, such as "industrial waste pond" or "cooling pond." This does not include the features related to sewage treatment, fish farming, water filtration, or mining. 050 0108 Area to be submerged This code identifies a point placed in an area shown by symbols 702(A), 141.39(B), 541.57, 547.2 (C), or 2203.07(D). The symbol depicts the expected normal pool elevation. Generally, code the outer line as symbolized. However, on older 1:24,000-scale quads, if the outer line is shown as an indefinite shoreline, then code the outer line as shoreline (see code 050 0203 for further explanation). If an elevation value is shown on the shoreline defining the area, the elevation parameter code is added. Features within the area are double coded (i.e., stream (050 0412), area to be submerged (050 0108)). This area is used when a dam is under construction and the limits of the intended reservoir are known. 050 0109 Sewage disposal pond or filtration plant This code identifies a point placed in any area that relates to the treatment of sewage. These features may be shown by symbols 410(A); 112.5, 141.12 (B); 512.59, 547.3 (C); or 2203.03, 2205.12, 2205.13 (D). The features are labeled in various ways such as "sewage disposal pond" or "filtration bed." This code is also applied to ponds that are unlabeled but are shown by symbols 700(A), 147.3(B), or 2106.07(D) and are located adjacent to a labeled sewage disposal plant. When this symbol is 0.030 inch in diameter, digitize as a degenerate line. Use code 050 0200 for blue outlines or code 050 0201 for black outlines. On 1:100,000-scale maps the sewage disposal plant is digitized by placing the area point in symbol 147.3(B). The outline shown by symbol 112.5(B) is coded with 050 0201. 050 0110 Tailings pond or settling basin This code identifies a point placed in an area shown by symbols 323(A); 132.16, 134.2 (B); 532.22, 538.1 (C); or 2112.05(D); and labeled "tailings pond" or "settling basin." Use code 050 0204 for outline of pond when it is limited by the contour. Do not code the outline otherwise. 050 0111 Marsh, wetland, swamp, or bog This code identifies a point placed in any area shown by symbols 431(A), 143.1(B), 543.1(C), or 2205.05(D). If the area being digitized has no definite outline shown, the edge of the pattern is followed to delimit the area (see code 050 0204). Any portion of a wetland that is overprinted with blue as in symbols 433(A), 141.35, 143.2 (B), 543.2(C), or 2205.06(D), is digitized as a separate area with the code assigned to indicate that it is a marsh (050 0111) and is submerged (050 0612). Any portion of a wetland that is overprinted with green tint to indicate it is wooded, as in symbols 432(A) or 543.03(B), is digitized as a separate area with the code to indicate that it is a swamp (050 0111) coincident with Vegetative Surface Cover (059 0007). Any portion of a wetland that is overprinted with green\blue to indicate it is submerged wooded swamp, as in symbols 543.4(B) or 141.37(B), is digitized as a separate area with the code assigned to indicate that it is a marsh (050 0111), submerged (050 0612), and coincident with Vegetative Surface Cover (059 0007). The code 059 0007 does not apply to 1:100,000-scale maps (see figure 3-1). Any streams shown in wetland areas are digitized as separate features (see code 050 0412). 050 0112 Mangrove area This code identifies a point placed in an area shown by symbols 437(A); 144.1, 152.4 (B); 544.1, 552.4 (C); or 2205.08, 2402.06 (D). If the outline of the area is not clearly defined, the edge of the pattern is followed to delimit the area (see code 050 0204). 050 0113 Rice field This code identifies a point placed in an area shown by symbols 436(A), 548.1(C), or 2205.07(D). If the outline of the area is not clearly defined, the edge of the pattern is followed to delimit the area (see code 050 0204). This code does not apply to 1:100,000-scale maps. Area Parameter Area Feature attribute attribute code code 1 Woods --- ---- ---- 2 Submerged woods 050 0421** 059 0007* (wooded lake) 3 Submerged wooded swamp 050 0111, 059 0007* 050 0612** 4 Wooded swamp 050 0111 059 0007* 5 Swamp 050 0111 ---- 6 Submerged swamp 050 0111, ---- 050 0612** ---- 7 Lake 050 0421** ---- * This code does not apply to 1:100,000-scale maps. ** If area meets minimum size criteria, add interpolated elevation attribute code and appropriate elevation value. Figure 3-1 Attribute and parameter coding for hydrography coincident with vegetative surface cover 050 0114 Cranberry bog This code identifies a point placed in each section of an area shown by symbols 438(A), 141.36(B), 541.49(C), or 2205.09(D) and labeled "cranberry bog." There may be several cranberry bogs in a group with one label "cranberry bogs." Code the outer line intermittent shoreline (see codes 050 0610 or 050 0200). The ditch pattern is digitized as shown and coded intermittent ditch (see codes 050 0610 or 050 0414). 050 0115 Flats (tidal, mud, sand, or gravel) This code identifies a number of features that fall into the general category of flats (e.g., foreshore flats, areas inside of rock reefs, and the area between the shoreline and sounding datum line on topographic-bathymetric editions). These features are shown by symbols 232(A), 316(A), 517.1(C), or 2113.01(D). On topographic- bathymetric editions, flats are shown by 135.7(B) or 535.10(C). The area is usually labeled by type, that is, mud, tidal, gravel, sand, or shell. Do not include in this classification features such as sand dunes, sand in open water (see 050 0423), or beach areas on dry land. Use code 050 0204 for the outline of an area that is not otherwise symbolized with a shoreline feature. 050 0116 Bays, estuaries, gulfs, oceans, or seas This code is used to identify a seaward area of water. The inland extent is defined at the place where a double-line stream reaches a width of l nautical mile (6,080 feet) with no further constrictions, if the conformation of the land and water do not otherwise make the division obvious. A closure line is placed to separate the bay, estuary, gulf, ocean, or sea from a double-line stream (050 0202). 050 0117 Shoal This code identifies a shoal area shown by symbols 243(A), or 512.142(C) and labeled "Shoal." This code does not apply to 1:100,000-scale maps. 050 0118 Soda evaporator This code identifies an area shown by symbols 439(A), 141.15(B), 541.27(C), or 2205.10(D) and labeled. On the 1:100,000-scale maps, symbol 141.15(B) with a blue dot or blue dash fill is used. The pattern of ditches is digitized and coded (see code 050 0414). 050 0119 Duck Pond This code identifies an area labeled "Duck Pond." This feature is shown by symbols 141.17, 146.2 (B) or 541.29, 546.2 (C). Generally, code the outer line as symbolized. However, on older 1:24,000- scale quads, if the outer line is shown as an indefinite shoreline, then code the outer line as intermittent shoreline (see code 050 0203 for further explanation). The ditch pattern is digitized as shown and coded intermittent ditch (see codes 050 0610 or 050 0414). 050 0120 Void area This code identifies an area on the source where hydrographic data do not exist or are interrupted because of replacement by imagery or a pattern from another category. A void area is also found beyond the national boundary to distinguish it from the background area. Where appropriate, the perimeter of the void area, usually a closure line, is coded as coincident with the category whose pattern defines the hydrographic void area. The closure line that defines the void area beyond the national boundary is coded as coincident with the Boundaries category (059 0009). 050 0121 Obstruction area in water area This code identifies an obstruction area in a water area shown with a double dashed line and labeled "Pipelines obstruction area," "Cable area," "Pipeline area," or "Cable-Pipeline area." By definition, this denotes water area and therefore the area is not double-coded. Arbitrary closure lines are required to complete the definition of an open-ended area. The limits of the area are not otherwise coded.3.5.4 Line Attribute Codes 050 0200 Shoreline This code identifies a natural shoreline shown by symbols 400(A), 141.1(B), 541.1(C), or 2203.01(D) and islands larger than 0.030 inch in diameter. The shoreline of an intermittent water body is coded 050 0200 and 050 0610 (intermittent). This code is also used to define the shorelines of double-line streams and ditches when the direction of flow cannot be determined (when direction of flow can be accurately determined, use codes 050 0605 and 0606). This code is also used to identify the shoreline of islands, lakes, and reservoirs that are digitized as degenerate lines. 050 0201 Manmade shoreline This code identifies the shoreline around or along a body of water to indicate that the shoreline is shown by a black outline. Where the shoreline is broken by a single-line pier, wharf, or jetty, the single-line feature is not digitized as part of the manmade shoreline. This code is also used to identify the shoreline of islands, lakes, and reservoirs that are digitized as degenerate lines. 050 0202 Closure line This code identifies a line segment digitized to form the closure of an areal feature whose outline is not explicitly symbolized. It is used, for example, as a line between hydrographic areas to retain the separate identity of each, such as where a double-line stream enters a lake or bay. This code also identifies a line segment used to close gaps in streams where the symbol has been broken. When this code is used as an arbitrary extension, the primary code should be used also. A closure line is used to define the extent of a void area that is not otherwise symbolized. 050 0203 Indefinite shoreline This code identifies a line shown by symbols 401, 415 (A); 141.3(B); 541.3(C); or 2203.02(D); which indicates that the shoreline cannot be definitely established. Note that on 1:24,000-scale quads compiled using older Part 6 symbology an indefinite shoreline was shown around hydrographic features that are now shown with an intermittent shoreline (intermittent ponds, dry lakes, duck ponds, inundation areas in non-coastal areas) or a shoreline (area to be submerged). On these quads, code these lines as intermittent shoreline or shoreline, not indefinite shoreline. 050 0204 Apparent limit This code identifies a line digitized around various fea-tures represented by an areal pattern when a definite out-line does not exist. The edge of the pattern (such as marsh or wash) is followed as closely as possible and carries this code to indicate the arbitrary nature of the line. 050 0205 Outline of a Carolina bay This code identifies a line shown by symbols 401(A), 141.7(B), 541.17(C), or 2205.19(D). The feature is outlined by a dashed blue line and is noted on the map collar. Any other hydrologic feature within the area of a Carolina bay, such as marsh, lake, or ditch, is digitized as a separate feature. If a bay outline is a complete and closed ellipse, the interior area does not have an attribute code unless it is a hydrologic feature in its own right. 050 0206 Danger curve This code identifies a line shown by symbol 244(A), which represents the limit of an area considered to be dangerous for navigation. 050 0207 Apparent shoreline This code identifies a line shown by symbols 141.2(B) or 541.2(C), which represents a coastal shoreline in areas of marsh, grass, mangrove, or other similar marine vegetation. This symbol is shown at the outer edge of vegetation, instead of the mean high-water line, and is used with topographic-bathymetric maps only. 050 0208 Sounding datum This code identifies a line shown by symbols 141.40(B) and 541.59(C), which represents the starting elevation (0) for bathymetric contours and is the mean lower low-water line. This symbol is found on topographic-bathymetric maps only. 050 0209 Low-water line In areas where the shoreline is undetermined or varies because of meteorological or other conditions, double-line streams are shown with the following symbols (starting onshore): a dashed (indefinite) shoreline, "area subject to inundation" fill, a line of small dashes (the marsh outline symbol) indicating mean low water or mean lower low water, and then the blue fill. This code identifies a line shown by symbols 541.47(C) and 546.1(C), which represents the mean low-water or mean lower low-water line. 050 0299 Processing line Some routines in the processing software (PROSYS) have limitations on the number of lines, nodes, or areas that can be processed. For example, an area may be associated with no more than 4,751 lines. This code describes a line or lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed. 3.5.5 Single-Point Attribute Codes 050 0300 Spring This code identifies a point placed in the center of the circular portion of a feature shown by symbols 427(A), 141.25(B), 541.40(C), or 2205.03(D) and labeled. When the center of the circular portion of the spring symbol does not fall directly on a linear feature in this overlay, it is digitized as a degenerate line. However, when the center of the circular portion of the spring symbol occurs directly on a linear feature, such as a stream, it is digitized as a node. In this case the tail of the spring is ignored and the node is connected to the stream element by digitizing a line following the general alignment of the stream on the source, and this line is coded consistent with the stream. In the case where the spring is the origin of a single-line stream, apply the code for spring to the node along with 050 0001. 050 0301 Nonflowing well This code identifies a point placed on a feature shown by symbols 426(A), 141.26(B), 541.39(C), or 2205.02(D) and labeled. In areas where wells are numerous, they may not all be labeled but are still digitized. This code may also be used on a node when the well symbol occurs directly on a line that is being digitized in the hydrographic overlay. A well is assumed to be nonflowing when labeled only as "Well." 050 0302 Flowing well This code identifies a point placed on a feature shown by symbols 426(A), 141.26(B), 541.39(C), or 2205.02(D) and labeled "Flowing well". This code may also be used on a node when the well symbol occurs directly on a line that is being digitized in the hydrographic overlay. 050 0303 Riser This code identifies a point placed on a feature that is shown by the located object symbol 198(A) or 2111.03(D) and labeled "riser." A riser is a vertical overflow pipe controlling the water level in a reservoir. 050 0304 Geyser or vent This code identifies a point placed on a special type of spring that ejects hot water or steam periodically. This includes gas vents, mud pots, fumaroles, and steam vents. It is shown by symbols 427(A), 141.26(B), 541.39(C), or 2205.03(D) and labeled. 050 0305 Windmill This code identifies a point placed on a well shown by symbols 199(A), 112.3(B), 512.69(C), or 2111.04(D). If the label indicates the well is dry or salt, use codes 050 0614 or 050 0608 in addition. 050 0306 Cistern This code identifies a point placed on a feature shown by symbols 426(A), 141.26(B), 541.39(C), or 2205.02(D) and labeled "cistern." This code may also be used on a node when the symbol occurs directly on a line that is being digitized in the hydrography overlay. 3.5.6 General Purpose Attribute Codes 050 0400 Rapids This code identifies rapids that are digitized as a node, area, or line, depending on the symbol treatment on the source. When rapids are shown by double ticks across a single-line stream as in symbols 443(A), 141.32(B), 541.54(C), or 2205.17(D), digitize a node between and equidistant from the points where the ticks intersect the stream. When shown by several ticks across a single-line stream, digitize a node at the beginning and ending points where the ticks intersect the stream and apply this code to the section of line between the nodes. If the rapids are shown by double ticks across a narrow double-line stream, as in symbols 141.32(B), or 541.54(C), digitize a line from bank to bank that is between and equidistant from the two ticks. In the case where the rapids are shown by a pattern of ticks as in symbols 442(A), 141.31(B), 541.53(C), or 2205.16(D), then digitize an area point in the rapids and identify it with this code. The limit is digitized with a closure line (050 0202) from bank to bank along the upstream and downstream edges of the ticks. The rapids area is implicitly part of the stream and does not need to be coded as "stream." 050 0401 Falls This code identifies a node placed where the tick mark in symbols 441(A), 141.30(B), 541.52(C), or 2205.15(D) intersects a single-line stream to show a small falls. It also identifies a digitized line that follows the upstream edge of symbols 440(A), 141.29(B), 541.51(C), or 2205.14(D) to depict a large falls on a double-line stream. In the case of a tick mark across a narrow double-line stream as is shown in symbols 141.30(B) or 541.52(C), digitize a line along the tick and identify it with this code. 050 0402 Gravel pit or quarry filled with water This code identifies a body of water that has formed naturally in a manmade excavation. It is labeled as gravel pit or quarry. If the feature is 0.030 inches or less in diameter, it is digitized as a degenerate line. If it is greater than 0.030 inch in diameter, it is digitized as an area. 050 0403 Gaging station This code identifies a point placed on symbols 200(A), 112.45(B), 512.113(C), or 2111.05(D). If the center of the gaging station symbol occurs directly on a line, such as a single-line stream or bank of a double-line stream, it is digitized as a node on that line. If the center of the symbol is placed off the line, digitize as a degenerate line. 050 0404 Pumping station This code identifies a point placed on symbols 201(A), 163(A), 112.7(B), or 2111.06(D) and labeled. If the feature is shown with the minimum size building symbol, 163(A), and occurs directly on a digitized line, it is coded as a node. If it is separate from the line and shown with the minimum size building symbol, 163(A), it is digitized as a degenerate line. If the feature is shown to scale, 165(A), it is digitized as an area. 050 0405 Water intake This code identifies a point placed on a labeled water intake shown by symbols 198(A) or 2111.03(D). If the symbol is on a digitized line, it is digitized as a node. If the symbol is separate from the line, it is digitized as a degenerate line. This code does not apply to 1:100,000- scale maps. 050 0406 Dam or weir This code identifies a feature shown by symbols 152, 153, 313 (A); 112.63, 132.14 (B); 512.34, 512.35, 532.9 (C); or 2108.01, 2108.02, 2302.08 (D). The feature may be labeled or named. A weir may be labeled "diversion weir". The code is used as a line code when the dam is shown by a line. When the dam is shown by contouring, digitize the straight segment of the shoreline of the impounded water, parallel to the contouring, and code as dam. In general, a single-line dam is digitized uniquely, and not double coded as shoreline. If the dam is carrying a road as in symbols 155(A), 112.65(B), 511.20, 512.37 (C), or 2108.04(D), digitize a centerline equidistant from the two road casings and use code 059 0017 as well to indicate the coincidence. The code is used as an area code when the dam is a large structure depicted to scale. The outer limits of the dam generally are unattributed, except the edge defining a shoreline, which is coded with the appropriate shoreline code. The radiating lines within symbol 153(A) are not digitized. See code 050 0407 for treatment of lock as in symbols 154(A), 112.64(B), 512.36(C), or 2108.03(D). If the dam is of earthen construction also use code 050 0618. 050 0407 Canal lock or sluice gate This code identifies canal locks or sluice gates shown by symbols 160, 161, 154 (A); 112.66(B); 512.36, 512.38 (C); or 2108.08, 2108.09, 2108.03 (D). It is used as a node or line code depending on the size of the feature. Symbols 160(A) or 2108.08(D) are digitized as nodes on the single-line stream. Symbols 161(A) or 2108.09(D) are digitized as lines across a double-line stream. The lock symbol within symbols 154(A) or 2108.03(D) is digitized as a node on the dam line if shown at symbol size (0.075 by 0.033 inch). If digitized to scale and larger than the symbol, the outline of the lock is digitized and coded. Some major rivers have extensive structures shown to scale for which the lock code is used on the enclosed areas of the structures as well as any linear extent. The enclosed water areas are not coded as stream because that information is implied by the feature. 050 0408 Spillway This code identifies a spillway, which is shown on a map in various ways. The spillway is digitized as a node, area, line, or degenerate line according to the size of the feature. If it is shown by a small circle or dot, it is digitized as a degenerate line. If the feature is shown by drainage lines, perennial or intermittent, it is digitized as a line. If the spillway is indicated by an arrangement of contour lines or a black box, it is digitized as an area. If a spillway is represented as an integral part of the dam, this code and an elevation value (if applicable) are assigned to a node on the digitized line of the dam. Some judgment is required to correctly digitize the spillway, as the feature is not always labeled. The label "Spillway elevation NNNN" placed in the impounded water area is sometimes the only reference to the feature. If the feature itself is represented by a label only, this code and the elevation value are assigned to a node placed on the digitized shoreline near the label. 050 0409 Gate (flood, tidal, head, or check) This code identifies a variety of labeled features used to control or divert the flow of water. These features are shown by a tick or black line. If shown by a tick on a single-line stream, a node is digitized and coded. If shown by a line on a double-line stream, the line is digitized and coded. 050 0410 Rock This code identifies a rock or group of rocks shown by symbols 236, 237, 238, 246 (A); 112.97, 112.98, 112.99 (B); 512.136 through 512.138, 512.160 (C); or 2113.03, 2113.04 (D). A rock shown by symbols 236, 237 (A); 112.97(B); 512.136, 512.137 (C); or 2113.03(D) is digitized as a degenerate line. A group of rocks less than 0.030 inch diameter is also digitized as a degenerate line. If the rocks are shown by symbols 238(A), 112.98(B), 512.138(C), or 2113.04(D), the outline is digitized but not coded; a point is placed in the area and coded. A sunken rock shown by symbols 246(A), 112.99(B), or 512.160(C) is digitized as a degenerate line and is assigned this code as well as code 050 0612 (sunken). 050 0411 Crevasse (glacial) This code identifies crevasse lines and crevasse areas depicted by symbol 453(A). If the crevasse area contains less than four lines, the individual lines are digitized. Crevasse areas that contain four or more lines are digitized as an area. The edge of the crevasse pattern is digitized as an apparent limit (see code 050 0204). This code does not apply to 1:100,000-scale maps. 050 0412 Stream This code identifies all naturally flowing water except braided streams (see code 050 0413). Streams are shown by symbols 402, 403, 405, 406, 408 (A); 141.4, 141.5, 141.6 (B); 541.4, 541.5, 541.7, 541.8, 541.10, 541.11 (C); or 2202.01, 2202.02, 2202.05 (D). Single-line streams are digitized as lines. Double-line streams are digitized as areas. The limits of the double-line stream area are formed by the left and right banks (see codes 050 0605 and 050 0606), by a closure line (code 050 0202) to separate the stream from a hydrographic area that it enters, or by the neatline. The course of a submerged stream in an impounded water area is digitized as a separate area with the stream code and the descriptive code for submerged (code 050 0612). The dashed blue lines are generally digitized as unattributed lines. Use the appropriate descriptive codes for streams that are intermittent or unsurveyed. In some cases an appropriately symbolized natural stream course will carry a ditch label; however, do not code as ditch. 050 0413 Braided stream This code identifies braided streams that are shown by symbols 404(A), 541.6, 541.9 (C), or 2202.03(D). A braided stream is a special case where the stream subdivides into interlacing channels. In map compilation, where possible, the actual channels are shown. However, if the channels are extremely complex or obscured by vegetation, the outer limit is scribed accurately and the inner channels are represented by a conventional pattern. The use of pattern versus actual channel is not noted on the map. Therefore, the braided portion of a stream is digitized as an area that carries this code. The outer limits are digitized and carry left and right bank codes (see codes 050 0605 and 050 0606). The braided area is separated from a double-line stream by a closure line (code 050 0202) and from a single-line stream by nodes (see codes 050 0004 and 050 0005). 050 0414 Ditch or canal This code identifies any manmade, flowing water feature used for irrigation, drainage, or transportation shown by symbols 416 through 422 (A); 141.19, 141.20 (B); 541.31 through 541.33 (C); or 2204.01 through 2204.06 (D). These may be labeled or unlabeled. Manmade water courses, of various shapes, are included in this code, even if not labeled. If an obviously natural stream course carries a ditch label, do not use this code. Some natural streams have portions that appear to have been realigned by man. If the artificial portion of a natural stream is not identified by a label or name change, do not use this code. The banks of double-line ditches and the points of origin or where single-line canals or ditches join water bodies are coded and digitized in the same way as they are for streams when the direction of flow can be determined. Navigable canals used for transportation have an additional code added to preserve this information (code 050 0616). Use additional descriptive codes to identify canals that are abandoned, intermittent, and so on. 050 0415 Aqueduct This code identifies features represented by symbols 418, 419, 421, 423, 424, 425 (A); 141.19 through 141.23 (B); 541.31 through 541.36 (C); or 2204.03, 2204.04, 2204.06 through 2204.09 (D), which are labeled "Aqueduct." Single-line aqueducts are digitized as lines. Double-line aqueducts are digitized as areas. The banks and inter-sections of aqueducts with water bodies are digitized and coded in the same manner as streams. An aqueduct that goes into an underground water tunnel is shown by symbols 424(A), 141.23(B), 541.35(C), or 2204.08(D) regardless of size. Therefore, the portion of the aqueduct that is in the tunnel is digitized as a line and carries the code for tunnel (050 0604) in addition to the aqueduct code. This code combination is also used for a feature shown by symbol 424 but labeled water tunnel. Use additional descriptive codes to identify aqueducts that are abandoned, elevated, or underground. 050 0416 Flume This code identifies features that are shown by symbols 418, 419, 421, 423, 425 (A); 141.19 through 141.22 (B); 541.31 through 541.34, 541.36 (C); or 2204.03, 2204.04, 2204.06, 2204.07, 2204.09 (D) and labeled "Flume." A flume is an artificial open inclined channel that conveys water for a special purpose and is frequently an elevated feature. A single-line flume is digitized as a line. A double-line flume is digitized as an area. The banks and the points where flumes intersect water bodies are coded and digitized in the same manner as streams. Use additional descriptive codes to describe flumes that are abandoned or elevated. 050 0417 Penstock This code identifies a feature that is shown by symbols 423, 425 (A); 141.21(B); 541.34, 541.36 (C); or 2204.07, 2204.09 (D) and labeled "Penstock." A penstock is an underground or exposed pipe conveying water from a canal or a dam to a hydroelectric plant. It is usually shown as a single-line feature, that is digitized as a line. The penstock may be carried underground in an aqueduct tunnel, symbols 424(A), 141.23(B), or 2204.08(D), in which case the single line is digitized and carries the additional code for tunnel (050 0604). In the event that a penstock is shown as a double-line feature in itself, it is digitized as an area. The banks and intersections with water bodies are coded and digitized in the same manner as streams. 050 0418 Siphon This code identifies features shown by symbols 452(A), 141.21(B), 541.41(C), or 2205.18(D). A siphon is a pipe conveying water to another level, either over or under an obstruction. On 1:24,000-scale maps, the dashes in the symbol may be omitted on siphons less than 200 feet long and a wing tick or break in the underpassing symbol used instead. On 1:100,000-scale maps a siphon is labeled. A single-line siphon is digitized as a line. A double-line siphon is digitized as an area. The limits of the area are unattributed. Use the code to indicate overpassing (050 0602) or underpassing (050 0617) on the portion of the siphon that crosses the obstruction. The code for overpassing is used if the relationship of the features is not clear on the source material. 050 0419 Channel in water area This code identifies a feature shown by symbols 444(A); 112.94, 141.9, 141.34 (B); or 512.154 through 512.156, 541.15, 541.16 (C). A channel in a water area shown with a double line is digitized as an area feature. By definition, this code denotes water area and therefore the area is not double coded. Arbitrary closure lines are normally required to complete the definition of an open-ended channel. The limits of the area are not otherwise coded. This code does not apply to submerged river courses in inundated areas. Use this code to identify an airboat trail, canoe trail, or wilderness waterway shown by one of the symbols listed above. See code 050 0616 for the application of the "navigable" descriptive code to channels. 050 0420 Wash or ephemeral drain This code identifies features shown by symbols 317, 409 (A); 134.1, 141.6 (B); 534.3, 541.13 (C); or 2112.04, 2202.06 (D). A wash is encoded as a hydrographic feature because it is an integral part of a stream network, generally found in arid areas and often associated with intermittent drainage. This code applies to symbols 409(A), 141.6(B), 541.13(C), or 2202.06(D) only when the feature is labeled as a wash. Any single-line drainage that is found in an areal wash, shown by symbol 541.14(C), is coded as appropriate. A wash is an ephemeral drainage feature because it is normally dry, but can contain runoff from heavy storms or snowmelt for a few hours. The edge of an areal wash pattern is coded as apparent limit (050 0204), unless the limits are defined by a hydrographic feature such as a double-line intermittent stream, then it is coded as right bank (050 0605) or left bank (050 0606), and intermittent (050 0610). Perennial features labeled as wash carry only the perennial stream code. Sand areas adjacent to double-line perennial streams are not coded as washes, but as sand in the Non- Vegetative Features category. 050 0421 Lake or pond This code identifies a natural body of water of any size. Lakes or ponds are shown by symbols 410, 411, 412, 414 (A); 134.7, 141.12, 141.13, 141.14 (B); 541.23, 541.25, 541.26 (C); or 2203.03, 2203.04, 2203.05, 2203.06 (D). This classification includes also impounded rivers that are labeled "Lake." A lake or pond that is 0.030 inch or less in diameter is digitized as a degenerate line. If the lake or pond is 0.030 inch or less in diameter and has a drain attached, it is digitized as a node. Any lake or pond larger than 0.030 inch is digitized as an area feature. The limits of the lake or pond are coded with the appropriate shoreline code. 050 0422 Coral reef This code identifies a coral reef or rock reef shown by symbols 233, 234 (A); 135.8, 112.100 (B); 512.135, 517.2, 517.3, 535.11 (C); or 2113.02(D). A coral reef or rock reef is digitized as an area if greater than 0.030 inch in diameter. An unattributed line is digitized around the outside of the reef pattern. If there is a brown tint inside the reef pattern, the inference is that the reef uncovers at low water and the area should also be coded as "flat" (050 0115). If there is no brown tint inside of the reef pattern, the inference is that the reef is always submerged and the area should be coded only (050 0422). If the coral reef or rock reef is shown by a symbol of 0.030 inches or less, it is digitized as a degenerate line. 050 0423 Sand in open water The code identifies an area of sand in other than tidal waters. It is shown by symbols 322(A), 134.3(B), 534.4(C), or 2112.03(D). The sand is digitized as an area if greater than 0.030 inch in diameter or as a degenerate line if 0.030 inch or less. The edge of the sand pattern is digitized as an apparent limit (050 0204) unless defined by a hydrographic limiting feature. 050 0424 Spoil area, dredged area, or dump area This code identifies a feature labeled "Spoil area", "Dredged area" or "Dump area." When shown by symbols 401(A) or 2203.02(D), it is digitized as a line. If shown by symbols 112.95(B) or 512.157(C), with or without blue tint in the enclosed area, it digitized as an area. When shown by two parallel dashed black lines without blue tint between them, it is also digitized as an area with a closure line on each end. Lines depicting the limits of the area are unattributed. By definition, spoil areas are located in water areas and therefore are not double coded. 050 0425 Fish ladder This code describes a feature shown by symbol 512.39(C) or shown as a labeled portion of a stream. When symbol 512.39(C) is depicted, the outline is coded 050 0201 (manmade shoreline) if shown in black or 050 0200 (shoreline) if shown in blue, and the area inside is coded with this attribute. When a section of a double-line stream is labeled, the upstream and downstream area limits are digitized as a closure line (050 0202), the shoreline is coded right bank or left bank (050 0605, 050 0606), and the area is attributed with this code. If a portion of a single-line stream is labeled, unattributed nodes are placed at the upstream and downstream limits, and the linear portion of this feature is attributed with this code. A fish ladder, that is symbolized as a labeled portion of a stream feature, is not double coded with the stream code. 050 0426 Holiday area This code identifies an inadequate survey area feature shown by symbols 112.93(B) or 512.153(C) and labeled "holiday area." The limits of this area are uncoded. 3.5.7 Descriptive Attribute Codes - apply to multiple types of feature 050 0601 Underground This code describes a feature that is labeled "underground" other than a tunnel, such as an underground aqueduct shown by symbols 423(A), 141.21(B), 541.34(C), or 2204.07(D). This code is not used to describe a portion of a feature that is placed underground to pass under another feature. (See code 050 0617.) 050 0602 Overpassing This code describes a feature or section of a feature that passes over rather than intersects another feature. The code is generally applied to a linear hydrographic feature carried over another feature in a manmade object, such as an aqueduct over a stream. The code is applied only to the overpassing portion of a longer elevated feature or to a section of a feature between wing ticks that is raised just to cross the obstruction. In some instances, such as a double-line stream passing over an aqueduct, the relationship of the feature is shown more simply by using code 050 0617 on the underpassing feature rather than using the overpassing code, because only one of the two conditions need be coded. 050 0603 Elevated This code describes a feature that is raised above ground level and is either labeled "elevated," or has wing ticks to indicate the elevated portion, as in symbols 425(A), 141.22(B), or 2204.09(D). This code is not used to describe any portion of a feature that is raised at some point in order to pass over another feature. (See code 050 0602.) 050 0604 Tunnel This code describes any portion of a feature that is carried through a tunnel as indicated by symbols 424(A), 141.23(B), 541.35(C), or 2204.08(D) or by a label. The code applies only to the portion of the feature that is in the tunnel. The concept of a tunnel conveys the idea of underground or underpassing. Therefore the additional attributes 050 0601 or 050 0617 are not used. 050 0605 Right bank This code describes the limit of a double-line feature, such as a stream, that would be on the right side if one were facing downstream. 050 0606 Left bank This code describes the limit of a double-line feature, such as a stream, that would be on the left side if one were facing downstream. 050 0607 Under construction This code describes any feature that has a label indicating that it was under construction at the time the map was made, typically canals or dams. 050 0608 Salt This code describes any feature, such as a marsh or well, that is labeled "salt." 050 0609 Unsurveyed This code describes stream features shown by symbols 408(A); 141.5(B); 541.03, 541.10, 541.11 (C); or 2202.05(D); which indicates a stream is unsurveyed, or any other feature that is labeled "unsurveyed." 050 0610 Intermittent This code describes any hydrographic feature, such as stream, pond, or canal, that is depicted by an intermittent symbol, such as 405, 412, 417, 420 (A); 141.6(B); 541.7, 541.32 (C); or 2202.02, 2203.05, 2204.02, 2204.05 (D). This code overrides the default value of "perennial" that is assumed in the basic codes. 050 0611 Abandoned or discontinued This code describes any feature that is labeled "abandoned" or "discontinued." 050 0612 Submerged or sunken This code describes any hydrographic feature that was overprinted by blue tint to indicate it is submerged, such as a marsh or an old river course in an impounded water area. This code is not used to define water channels (050 0419). It is also used to describe features labeled "sunken." The outline of the submerged river course is generally digitized as an unattributed line. 050 0614 Dry This code describes any feature that is labeled "Dry," such as a dry lake, shown by symbols 134.7(B) or 534.5(C), or dry well. 050 0615 Mineral or hot (sulphur, alkali, and so on) This code describes any well, spring, or water source that is labeled to indicate the water is hot or contains minerals. The labels vary according to the substance in the water. 050 0616 Navigable - transportation This code describes any canal that is labeled as navigable and is therefore a transportation feature. It is also used for channels intended for transportation, such as the Intracoastal Waterway. 050 0617 Underpassing This code describes a feature or a section of a feature that passes underneath, rather than intersects, another feature. This code is generally applied to a linear feature, such as an aqueduct under a canal. In some cases, such as a single-line stream passing under a siphon, the relationship is more simply shown by using code 050 0602 on the overpassing feature rather than using the underpassing code, because only one of the two conditions need be coded. 050 0618 Earthen construction This code describes a dam that is earthen in construction as is shown in symbols 313(A), 132.14(B), 532.9(C), or 2302.08(D). This feature must consist of two or more contours that are shown parallel to a straightened or near- straightened portion of the shoreline (which may or may not have a perennial drain attached) and (or) be labeled as a dam. This code (050 0618) and the code for dam (050 0406) are assigned to the straightened portion of the shoreline that parallels the contours. This code (050 0618) and the code for dam (050 0406) are also assigned to the portion of the shoreline of a lake or pond that is shown by a brown line. Do not apply this code to the shoreline of a lake or pond that is too small to require an interpolated elevation (050 0619) and that has an intermittent stream attached, for example, a stock pond. 050 0619 Interpolated elevation This code identifies a water surface elevation that is not printed on the graphic source but has been interpolated from adjacent hypsography. Interpolated elevations are applied when required to perennial and intermittent lakes, ponds, reservoirs, and other impounded bodies of water meeting a minimum size of 0.500 inch at map scale. The following descriptive attribute codes represent decimal fractions of feet or meters. They must only be used in conjunction with the elevation or river mile mark parameter attribute codes and only when the original elevations or river mile marks are expressed to decimal fractions or when applying interpolated elevations in extremely flat areas. The units will be the same as those of the corresponding parameter code. 050 0621 .1 050 0622 .2 050 0623 .3 050 0624 .4 050 0625 .5 050 0626 .6 050 0627 .7 050 0628 .8 050 0629 .9 3.5.8 Parameter Attribute Codes 05N ---- Elevation of actual, interpolated, or predicted water surface This code is used for the value of the water surface elevation shown on bodies of water. The value may be shown as "normal pool elevation XXX," "elevation XXXX," or simply as a value printed in blue or black. This code is also used for the value of the maximum potential water surface elevation shown on the indefinite shoreline defining the limits of an area subject to controlled inundation. The digitizer enters a value in place of the "N" in the major code as follows: 1 = whole feet 2 = whole meters 6 = whole feet below datum 7 = whole meters below datum The elevation value is then entered into the minor code, flush right. If a value in feet exceeds four digits, it is converted to meters. To express elevations in decimal feet or meters, use this parameter code in conjunction with descriptive attribute codes 050 0621 through 050 0629. 055 ---- River mile mark This code identifies a river mile mark as shown by symbol 512.109(C). The point is placed on the black cross next to the label "Mile NNN." If the cross occurs in the area of a double-line stream it is digitized as a degenerate line. If the cross occurs directly on a line that is also being digitized, the point is digitized as a node on that line. When the river mile mark is expressed to a decimal fraction, use this code 055 xxxx for the nondecimal value and 050 0621 through 050 0629 for the decimal value. Enter the value in the minor code flush right. If the source material has the value shown at intervals, such as at every fifth mark, the digitizer assigns the appropriate value to each mark. 050 0000 Photorevised feature This code is described in section 3.3.3. 058 0000 Best estimate of classification or position This code is described in section 3.3.3. 059 00-- Coincident feature This code is described in section 3.3.3. This sheet represents pages 3-14, which is blank (Current version containing all changes through 11/15/93) 3.6 VEGETATIVE SURFACE COVER--MAJOR CODE 070 Features that are collected under this code include woods or brush-wood, scrub, orchards or plantations, scattered trees, and vineyards. Additional vegetative features that are associated with wetland or submerged areas, such as marshes and swamps, rice fields, mangrove, and cranberry bogs, are collected under hydrography, major code 050. 3.6.1 General Principles Vegetative surface cover information is shown on the map source as an area of pattern or tint. Each area is digitized by following the edge of the open-window separate. If the open-window separate is not available, the line is digitized following the outline of the pattern or tint as closely as possible. The digitized line depicting the limits of the vegetative feature is 3.6 VEGETATIVE SURFACE COVER--MAJOR CODE 070 Features that are collected under this code include woods or brush-wood, scrub, orchards or plantations, scattered trees, and vineyards. Additional vegetative features that are associated with wetland or submerged areas, such as marshes and swamps, rice fields, mangrove, and cranberry bogs, are collected under hydrography, major code 050. 3.6.1 General Principles Vegetative surface cover information is shown on the map source as an area of pattern or tint. Each area is digitized by following the edge of the open-window separate. If the open-window separate is not available, the line is digitized following the outline of the pattern or tint as closely as possible. The digitized line are associated with wetland or submerged areas, such as marshes and swamps, rice fields, mangrove, and cranberry bogs, are collected under hydrography, major code 050. 3.6.1 General Principles Vegetative surface cover information is shown on the map source as an area of pattern or tint. Each area is digitized by following the edge of the open-window separate. If the open-window separate is not available, the line is digitized following the outline of the pattern or tint as closely as possible. The digitized line depicting the limits of the vegetative feature is depicting the limits of the vegetative feature is unattributed. However, the line digitized between features, to retain the separate identity of each, is coded as a closure line (070 0200). See figure 3-2. Note that in the vegetative surface cover category, there are no photorevised features shown in purple. Photorevised vegetation is shown in green and not distinguishable as such. 3.6.1.1 Vegetative Surface Cover Attribute Codes 3.6.1.1 Vegetative Surface Cover Attribute Codes The attribute codes authorized for use in digitizing the vegetative surface cover category are listed in this section. The instructions for the use of the attribute codes are given in section 3.6.2 through 3.6.8. o Node attribute codes None o Area attribute codes 000 0000 Outside area 070 0101 Woods or brushwood 070 0102 Scrub 070 0103 Orchard or plantation 070 0104 Vineyard 070 0105 Scattered trees 070 0106 Void area o Line attribute codes 070 0200 Closure line 070 0299 Processing line o Single-point attribute codes None o General purpose attribute codes None o Descriptive attribute codes None o Parameter attribute codes 078 0000 Best estimate of position or classification 079 00-- Coincident feature 3.6.2 Node Attribute Codes There are no attribute codes for nodes in this category. 3.6.3 Area Attribute Codes 000 0000 Outside area This code is described in section 3.3.3. 070 0101 Woods or brushwood Wooded areas contain tree cover or brush that is potential tree cover. The growth is at least 6 feet tall, is dense enough to afford cover for troops, and has a minimum density between 20 and 35 percent. Woods are shown by symbols 600, 604(A); 152.1, 152.2, 152.3, 152.5(B); 552.1, 552.2, 552.3, 552.5(C); or 2402.01(D). Woods which overprint swamp, submerged swamp, or open water areas will be delineated as separate from any contiguous wooded areas and will be coded as coincident with the hydrographic overlay as shown in Figure 3.2. 070 0102 Scrub Scrub areas are covered with low-growing or stunted perennial vegetation such as cactus, mesquite, or sagebrush. Scrub is common in arid areas and usually is not mixed with woods. It is shown by symbols 603(A); 154.1(B), 554.1(C), or 2402.05(D). 070 0103 Orchard or plantation Orchard or plantation areas consist of evenly spaced trees or tall bushes that bear fruit or nuts. Plantings of trees that are called groves are included in this type. These features are shown by symbols 601(A), 155.1(B), 555.1(C), or 2402.03(D). Area Parameter Area Feature attribute attribute code code 1 Woods 070 0101 None 2 Submerged woods, submerged wooded swamp, wooded swamp 070 0101 079 0005* 3, 4, 5 Not digitized in this category * This code does not apply to 1:100,000-scale maps. Figure 3-2 Attribute and parameter coding for woods, submerged woods, wooded swamp and submerged wooded swamp 070 0104 Vineyard Vineyards are plantings of grapevines or other kinds of cultivated climbing plants, such as berry vines and hops, supported and arranged evenly in rows. Vineyards are shown by symbols 602(A), 156.1(B), 556.1(C), or 2402.04(D). 070 0105 Scattered trees Scattered trees are woods or brushwood that are less than the minimum density required for woods (code 070 0101). Scattered trees are shown by symbol 553.1(C). 070 0106 Void area This code identifies the area on the source material where vegetative surface cover data do not exist because of replacement by imagery. This code is also used to identify the area beyond the national boundary to distinguish it from the background area. The closure line that defines the void area beyond the national boundary is coded as coincident with the Boundaries category (079 0009). 3.6.4 Line Attribute Codes 070 0200 Closure line This code describes a line digitized to define the perimeter of void areas that are not otherwise explicitly symbolized. This code also describes a line segment digitized between vegetative features to retain separate identity of each. See figure 3-2. 070 0299 Processing line Some routines in the processing system (PROSYS) have limitations on the number of lines, nodes, or areas that can be processed. For example, an area may be associated with no more than 4,751 lines. This code identifies a line or lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed. 3.6.5 Single-Point Attribute Codes There are no single-point attribute codes for this category. 3.6.6 General Purpose Attribute Codes There are no general purpose attribute codes for this category. 3.6.7 Descriptive Attribute Codes There are no descriptive attribute codes for this category. 3.6.8 Parameter Attribute Codes 078 0000 Best estimate of position or classification This code is described in section 3.3.3. 079 00-- Coincident feature This code is described in section 3.3.3. For the Vegetative Surface Cover category, the coincident feature parameter code is used for wooded swamps, submerged wooded swamps, or submerged woods. Figure 3-2 depicts an example. (Current version containing all changes through 11/15/93) 3.7 NON-VEGETATIVE FEATURES--MAJOR CODE 080 3.7.1 General Principles The purpose in digitizing non-vegetative features is to collect information about the natural surface of the Earth as symbolized on the map. This includes lava, sand, and gravel features. Numerous other non-vegetative features are included in the categories of Hydrography (major code 050) and Manmade Features (major code 200). Vegetative surface features are in the category of Vegetative Surface Cover (major code 070). The non-vegetative features information is primarily digitized as distinct areas (polygons) identified by an attribute code assigned to a point within the area. The outline of the area is digitized from the open-window separate used to prepare the map. If the separate is not available, the line is digitized by following the outline of the symbolized area as closely as possible. The outline of the coded area is not given an attribute code, unless it is coincident with a linear feature in another category. Non-vegetative features symbolized as point features, such as natural arches, are also digitized in this category. 3.7.1.1 Non-Vegetative Features Attribute Codes The attribute codes authorized for use in digitizing non- vegetative features are listed in this section and the instructions for the use of the codes are given in sections 3.7.2 through 3.7.8. o Node attribute codes None o Area attribute codes 000 0000 Outside area 080 0100 Glacial moraine 080 0101 Gravel beach 080 0102 Sand area or beach 080 0103 Shifting sand or dune area 080 0104 Lava 080 0105 Void area o Line attribute codes 080 0200 Closure line 080 0299 Processing line o Single-point attribute codes (degenerate line) 080 0300 Located surface feature o General purpose attribute codes None o Descriptive attribute codes None o Parameter attribute codes 080 0000 Photorevised feature 088 0000 Best estimate of position or classification 089 00-- Coincident feature 3.7.2 Node Attribute Codes There are no attribute codes for nodes in this category. 3.7.3 Area Attribute Codes 000 0000 Outside area This code is described in section 3.3.3. 080 0100 Glacial moraine A glacial moraine is an area of gravel deposited by a glacier. The glacier symbol (see code 050 0103) may be adjacent to the moraine. Areas where the glacial moraine pattern overlaps a glacier are coded coincident with the hydrography category (080 0005). The moraine is shown by symbols 320(A), 134.4(B), or 537.2(C). However, on 1:100,000-scale maps, the symbol is not labeled. Therefore, the feature must be examined with respect to the surrounding area to identify a moraine correctly. 080 0101 Gravel beach This code identifies an area shown by the gravel pattern USGS 22 or by symbols 329(A), 134(B), 537.1(C), or 2112.03(D) and labeled "gravel." Note that on 1:100,000-scale maps, the sand and gravel beaches are shown by the sand pattern USGS 17 and the only distinction made between them is the label "gravel." 080 0102 Sand area or beach This code identifies an area shown by the sand pattern, USGS 17 or by symbols 316(A), 134.3(B), or 534.1(C). A sand beach is not labeled on 1:24,000-scale maps, nor is there a separate symbol number, but is usually found bordering a large water body. On 1:100,000-scale maps, this code is used for all beaches as shown in symbol 134.5(B). On P-Maps this code is used for all areas and beaches as shown by symbol 2112.03(D) and labeled "sand." 080 0103 Shifting sand or dune area This code identifies an area shown by symbols 331(A), 134.6(B), 534.2(C), or 2112.03(D). Each symbol carries the label "sand dunes." On older maps shifting sand may be shown by USGS 17A, which is no longer in use. Such areas are also identified by this code. 080 0104 Lava This code identifies an area shown by symbols 328(A), 135.5(B), 535.6(C), or 2112.07(D) or outlined by symbol 532.24(C), all labeled "Lava." Such areas must be labeled to have this code assigned because the disturbed surface symbols are used for other features. 080 0105 Void area This code identifies an area on the source material, beyond the national boundary, where non-vegetative feature data do not exist because of replacement by imagery. This code is also used to identify the area beyond the national boundary to distinguish it from the background area. The closure line that defines the void area beyond the national boundary is coded as coincident with the Boundaries category (089 0009). 3.7.4 Line Attribute Codes 080 0200 Closure line This code describes a line digitized to define the perimeter of void areas that is not otherwise explicitly symbolized. 080 0299 Processing line Some routines in the processing system software (PROSYS) have limitations on the number of lines, nodes, or areas that can be processed. For example, an area may be associated with no more than 4,751 lines. This code describes a line or lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed. 3.7.5 Single-Point Attribute Codes 080 0300 Located surface feature This code describes a point placed on a landmark surface feature that is shown by symbols 198(A), 112.4(B), 412.72(C), or 2111.03(D) and labeled. Landmark surface features may include natural arches and natural bridges, which are not otherwise symbolized. 3.7.6 General Purpose Attribute Codes There are no general purpose attribute codes in this category. 3.7.7 Descriptive Attribute Codes There are no descriptive attribute codes in this category. 3.7.8 Parameter Attribute Codes 080 0000 Photorevised feature This code is defined in section 3.3.3. 088 0000 Best estimate of position or classification This code is defined in section 3.3.3. 089 00-- Coincident feature This code is defined in section 3.3.3. (Current version containing all changes through 11/15/93) 3.8 BOUNDARIES--MAJOR CODE 090 3.8.1 General Principles The purpose of digitizing boundaries is to convert into digital form the point and line information, displayed on a map source, that is part of the National Mapping Division base category denominated as boundaries. Map information normally considered to be in other base categories, but using symbology similar to that found in the boundaries category, e.g., cemetery, ruins, and drive-in theatre limits, is not included in the boundaries category. Counties, or county equivalents, may be divided into minor civil subdivisions. Quadrangle maps show only subdivisions that are reasonably stable. Incorporated places includes cities, towns, and villages, which may be subdivisions of the county, town, or township wherein they are located or may be coextensive with them or independent. Hawaii is divided into five counties. Four of the counties are subdivided into districts. Districts are subdivided into smaller areas called ahupuaas, and ahupuaas are subdivided into small land divisions called ilis and leles. The boundaries of ilis and leles are not collected. A further land subdivision shown on 1:24,000- Scale maps in Hawaii is the homestead. The homesteads are much smaller than the ahupuaas, generally less than a square mile. Line attribute codes are not attached to a boundary if they are implicitly defined by its bounding areas. For example, a civil township boundary is deducible as such from the area codes on either side of it. However, boundary lines that are coincident with features from other categories or that have been revised have the appropriate parameter or descriptive codes attached to the line segment itself, i.e., 099 00 or 090 0000. Boundaries are described in Topographic Instructions, Chapter 4a3, Boundaries on 1:24,000-Scale Maps (January 1980). 3.8.1.1 Boundaries Attribute Codes The attribute codes used in digitizing boundary information are listed in this section. Instructions for the use of the attribute codes are given in sections 3.8.2 through 3.8.6. o Node attribute codes 090 0001 Monumented point on a boundary o Area attribute codes 000 0000 Outside area 090 0100 Civil township, district, precinct, or barrio 090 0101 Incorporated city, village, town, borough, or hamlet 090 0103 National park, monument, lakeshore, seashore, parkway, battlefield, or recreation area 090 0104 National forest or grassland 090 0105 National wildlife refuge, wildlife management area, game preserve, or fish hatchery 090 0106 National scenic waterway, riverway, wild and scenic river, or wilderness area 090 0107 Indian reservation 090 0108 Military reservation 090 0110 Federal prison 090 0111 Miscellaneous Federal reservation 090 0129 Miscellaneous State reservation 090 0130 State park, recreation area, arboretum, or lake 090 0131 State wildlife refuge, wildlife management area, game preserve, or fish hatchery 090 0132 State forest or grassland 090 0133 State prison 090 0134 County game preserve 090 0135 Ahupuaa (Hawaii) 090 0136 Hawaiian homestead 090 0150 Large park (city, county, or private) 090 0151 Small park (city, county, or private) 090 0197 Canada 090 0198 Mexico 090 0199 Open water o Line attribute codes 090 0201 Indefinite (or approximate) boundary 090 0202 Disputed boundary 090 0203 Historical line 090 0204 Boundary closure line 090 0299 Processing line o Single-point attribute codes (degenerate line) 090 0301 Reference monuments for boundary points o Parameter attribute codes 090 0000 Photorevised feature 091 00-- State or State equivalent FIPS code 092 0--- County or county equivalent FIPS code 093 00-- Civil township or civil township equivalent FIPS code, first two digits 094 0--- Civil township or civil township equivalent FIPS code, last three digits 095 ---- Monument number 096 XXYY Alphabetic portion of any monument number Substitute numeric equivalent of alphabetic portion for XX and for YY as follows: 00 = blank, 01 = A, 02 = B, 03 = C, 04 = D, 05 = E, 06 = F, 07 = G, 08 = H, 09 = I, 10 = J, 11 = K, 12 = L, 13 = M, 14 = N, 15 = O, 16 = P, 17 = Q, 18 = R, 19 = S, 20 = T, 21 = U, 22 = V, 23 = W, 24 = X, 25 = Y, 26 = Z. 098 0000 Best estimate of classification or position 099 00-- Coincident feature 3.8.2 Node Attribute Codes 090 0001 Monumented point on a boundary This code describes a physical monument lying on a boundary line. This includes any of the following: o recovered section corners, quarter corners, closing corners, angle points, or meander turning points that fall on a boundary. These monuments are designated by symbols 506, 507, 510, 511, 523 (A); 523.5 through 523.7 (C); or 2502.07, 2502.08 (D). The coincidence code 099 0030 is also used. o survey control stations on a boundary. These monuments are designated by symbols 216 through 219, 222, 223, 225 through 227, 230, 231 (A); 512.99 through 512.107 (C); or 2102.02 through 2102.04, 2102.06 through 2102.09, 2102.12 (D). The coincidence code 099 0015 is used in all cases, and coincidence code 099 0030 is also used if the monument is coincident with the U.S. Public Land Survey System. o land grant monuments on a boundary. These monuments are designated by symbols 501(A) or 2502.02(D). The coincidence code 099 0030 is used. Land grants are digitized as part of Public Lands. o any other point represented with a red or black boundary monument symbol. If the monument is numbered, also use code 095 ----. 3.8.3 Area Attribute Codes 000 0000 Outside area This code is described in section 3.3.3. 090 0100 Civil township, district, precinct, or barrio This code identifies a point placed within an area delineated by symbols 205(A), 112.77(B), 512.126(C), or 2107.03(D). 090 0101 Incorporated city, village, town, borough, or hamlet This code identifies a point placed within an area delineated by symbols 206(A), 112.77(B), 512.127(C), or 2107.04(D). 090 0103 National park, monument, lakeshore, seashore, parkway, battlefield, or recreation area This code identifies a point placed within a national park, national monument, national recreation area, national seashore or lakeshore, national historic site, national parkway, or national battlefield. The following national areas are normally administered by the National Park Service and can be included under the national park attribute code: historic parks and places, memorial parks, natural landmarks, and national preserves. National cemeteries are included under the national park code and are given the coincidence code 099 0020. All areas with pink stippling along the boundary should be included under national parks unless the area label falls within one of the other Federal area categories. National park areas are delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0104 National forest or grassland This code identifies a point placed within a national forest or grassland delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0105 National wildlife refuge, wildlife management area, game preserve, or fish hatchery This code identifies a point placed within a wildlife recreation or management area, fish hatchery, animal range, or refuge for specific animals, and is delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0106 National scenic waterway, riverway, wild and scenic river, or wilderness area This code identifies a point placed within a national scenic waterway, riverway, wild and scenic river, or wilderness area. These areas are delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0107 Indian reservation This code identifies a point placed within an Indian reservation, including those that have boundaries symbolized with a solid red line. If the solid red line is labeled with the name "Old Indian Reservation Boundary" it should be assigned only the historical line code (see code 090 0203). Rancherias and Indian allotments are types of Indian reservations, all of which are delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0108 Military reservation This code identifies a point placed within a military reservation. Examples are: forts, bases, weapons stations, Coast Guard stations, and bombing and gunnery ranges. These areas are delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0110 Federal prison This code identifies a point placed within a Federal prison delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0111 Miscellaneous Federal reservation This code identifies a point placed within a Federal government reservation not included in any other Federal area category. An example is a veterans hospital. This code and code 090 0129 replace previous code 090 0109, Non-military Government Reservation. The area is delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0129 Miscellaneous State reservation This code identifies a point placed within a State equivalent government reservation not included in any other State area category. An example is State hospital. This code and code 090 0111 replace previous code 090 0109, Non- military Government Reservation. The area is delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0130 State park, recreation area, arboretum, or lake This code identifies a point placed within a State park, recreation area, arboretum, or lake delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0131 State wildlife refuge, wildlife management area, game preserve, or fish hatchery This code identifies a point placed within a State wildlife refuge, wildlife management area, fish hatchery, or game preserve delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0132 State forest or grassland This code identifies a point placed within a State forest or grassland delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0133 State prison This code identifies a point placed within a State prison area delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D). 090 0134 County game preserve This code identifies a point placed within a county game preserve delineated by symbols 207, 209 (A); 512.128, 512.129 (C); or 2107.05, 2107.06 (D). 090 0135 Ahupuaa (Hawaii) This code identifies a point placed within an area delineated by symbols 500(A), 112.78(B), 523.10(C), or 2502.01(D). Code 300 0103 is not used for ahupuaas because they are not part of the Public Land Survey System. More explanation of this code is given in section 3.8.1. 090 0136 Hawaiian homestead This code identifies a point placed within an area delineated by symbols 500(A), 112.78(A), 523.10(C), or 2502.01(D). Codes 090 0111 and 090 0129 are not used for Hawaiian homesteads because they are not reservations. More explanation of this code is given in section 3.8.1. 090 0150 Large park (city, county, or private) This code identifies a point placed within a regional, city, county, or private park delineated by symbols 207(A), 112.79(B), 512.128(C), or 2107.05(D). 090 0151 Small park (city, county, or private) This code identifies a point placed within a regional, city, county, or private park delineated by symbols 209(A), 512.129(C), or 2107.06(D). 090 0197 Canada This code identifies a point placed within the boundaries of Canada. The boundary between Canada and the United States is identified by symbols 202(A), 112.74(B), 512.123(C), or 2107.01(D). 090 0198 Mexico This code identifies a point placed within the boundaries of Mexico. The boundary between Mexico and the United States is identified by symbols 202(A), 112.74(B), 512.123(C), or 2107.01(D). 090 0199 Open water This code identifies a point placed within water areas on coastal quadrangles, which are not otherwise included within a coded area, such as 091 00xx-- State FIPS. 3.8.4 Line Attribute Codes 090 0201 Indefinite (or approximate) boundary This code identifies a boundary for which the accuracy of location does not meet National Map Accuracy Standards for well-defined features. Indefinite boundaries of county rank or higher appear on 1:100,000- and 1:24,000-scale maps with standard symbolization but reduced to one-half the specified lineweight and labeled "Indefinite Boundary." Those of less than county rank are shown with normal symbolization and lineweight and are labeled "Indefinite Boundary." Boundaries labeled "Approximate" on 1:24,000-scale maps are included under this code. Indefinite boundaries are depicted by symbols 212(A), 112.80(B), or 512.130(C). 090 0202 Disputed boundary This code identifies a State, county, or national reservation boundary that is unmarked and cannot be located on the ground from other substantial evidence, that has a disputed location, or that the recorded description of cannot be reconciled with local conditions. Disputed boundaries are labeled "Indefinite" on the map with an additional marginal note. 090 0203 Historical line This code identifies boundary lines that have some historical significance as indicated by a label. These include boundaries labeled with a name, old Indian treaty or allotment lines, historical State lines, and old military reservation boundaries (shown in red). 090 0204 Boundary closure line This code identifies lines digitized to complete unclosed boundaries. In the case of national, State, or county boundaries that stop at a shoreline, the shoreline is digitized and given this attribute. The offshore area is then given the appropriate area code. In the case where a national, State, or county boundary is extended out from shore and dropped, an arbitrary line is digitized by extending the line from the drop point to the quadrangle neatline and giving the new line the 090 0204 attribute code. The water area within the boundary is given the same code as the equivalent land area. 090 0299 Processing line Some routines in the processing system (PROSYS) have limitations on the number of lines, nodes, or areas that can be processed. For example, an area may be associated with no more than 4,751 lines. This code describes a line or lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed. 3.8.5 Single-Point Attribute Codes (degenerate lines) 090 0301 Reference monuments for boundary points This code identifies monumented points not on a boundary line, but serving as references to establish the location of points on the boundary. Reference monuments are delineated by symbols 226(A) or 512.105(C). If the monument is numbered, also use code 095 ----. 3.8.6 Parameter Attribute Codes 090 0000 Photorevised feature This code is described in section 3.3.3. 091 00-- State or State equivalent FIPS code Enter the two-digit State or State equivalent FIPS code. 092 0--- County or county equivalent FIPS code Enter the three-digit county or county equivalent (e.g., parish, independent city) FIPS code. 093 00-- Civil township or township equivalent FIPS code Enter the first two of the five-digit township or township equivalent FIPS code. 094 0--- Civil township or township equivalent FIPS code Enter the last three of the five-digit township or township equivalent FIPS code. 095 ---- Monument number Enter the one- to four-digit monument number, flush right. 096 XXYY Alphabetic portion of any monument number This code is used to encode the alphabetic portion of any monument number. The code is used in conjunction with the appropriate code 095 ---- if the monument designation is mixed numeric and alphabetic. The code can hold one or two letters by substituting the numeric equivalent 01 to 26 for the letters A to Z with 00 substituting for a blank. If one letter is encoded it will be entered in the YY portion of the code with blank coded into the XX portion. The code precedes or follows the numeric portion of the monument number in accordance with its actual position. In the case of an entirely alphabetic monument designator, also use the FIPS code to specify jurisdiction with 0000 entered into the minor code. The procedure for encoding the alphabetic portion of a monument number is identical to the procedure for encoding the alphabetic portion of a route number as described under code 177 XXYY. 098 0000 Best estimate of classification or position This code is described in section 3.3.3. 099 00-- Coincident feature This code is described in section 3.3.3. (Current version containing all changes through 11/15/93) 3.9 SURVEY CONTROL AND MARKERS--MAJOR CODE 150 3.9.1 General Principles The purpose of collecting Survey Control and Markers category data is to capture horizontal and vertical control information about the points of established horizontal and vertical positions that are used as fixed references in positioning and correlating map features. The vertical control data are digitized from the graphic source, and the survey control markers with horizontal control data are derived from ancillary source (i.e., geodetic control sheets). Not included are elevation data of less than third order, such as spot elevations, or the "T" and "AT" spot elevations on provisional maps. The features in this category are generally digitized as single-point features, also called degenerate lines. When these features are located directly on a linear feature in this overlay, they are collected as node elements. Each single-point feature is assigned a code to describe the type of control point or marker and appropriate parameter codes to designate the location and elevation. Each single- point feature is also assigned the State and county FIPS codes. Several of the control points and markers are coincident with points in the U.S. Public Land Survey System or in the Boundaries category. Such features are also assigned the coincident feature code. The list of codes used is in section 3.9.1.1 and instructions for their use are in sections 3.9.2 through 3.9.8. The codes that describe a photorevised feature and a best estimate of position/classification are not used in this category. Only one of the codes in this section is applicable to 1:100,000-scale maps, code 150 0331. 3.9.1.1 Survey Control and Markers Attribute Codes The attribute codes used in digitizing survey control features are listed in this section. Instructions for the use of the attribute codes are given in sections 3.9.2 through 3.9.8. o Node attribute codes None (See 3.9.1) o Area attribute codes 000 0000 Outside area 150 0100 Void area o Line attribute codes 150 0200 Closure line o Single-point attribute codes 150 0300 Horizontal control station, third order or better, permanent mark 150 0301 Horizontal and vertical control station, third order or better 150 0302 Horizontal control station, vertical angle bench mark (VABM) 150 0303 Horizontal control station, checked spot elevation 150 0310 Vertical control station, third order or better, tablet 150 0311 Vertical control station, recoverable mark, third order or better, no tablet 150 0320 Boundary monument, third order or better, tablet 150 0321 Boundary monument, third order or better, no tablet 150 0330 Reference monument 150 0331 U.S. mineral or location monument 150 0332 Other control point o General purpose attribute codes None o Descriptive attribute codes 150 0601 - 150 0609 Fractions of elevation values o Parameter attribute codes 151 ---- State or State equivalent FIPS code 152 ---- County or county equivalent FIPS code 153 ---- Elevation in feet 154 ---- Elevation in meters 155 ---- Elevation in feet below datum 156 ---- Elevation minus 10,000 for elevations greater than 9,999 feet 157 ---- Elevation in meters below datum 159 00-- Coincident feature 3.9.2 Node Attribute Codes There are generally no node attribute codes in this category. However, single-point features, which are generally digitized as degenerate line elements, are digitized as node elements when located on a line (200 - closure line) in this category. See sections 3.9.3, 3.9.4, and 3.9.5 for additional information. 3.9.3 Area Attribute Codes 000 0000 Outside area This code is described in section 3.3.3. 150 0100 Void area This code identifies an area on the source material where no survey control data exist because of replacement by imagery or a pattern from another category. A void area is also found beyond the national boundary to distinguish it from the background area. Where appropriate, the perimeter of the void area, a closure line, is coded as coincident with the category that defines the survey control void area. The closure line that defines the void area beyond the national boundary is coded as coincident with the Boundaries category (159 0009). 3.9.4 Line Attribute Codes 150 0200 Closure line This code describes a line digitized to define the perimeter of void areas. 3.9.5 Single-Point Attribute Codes Although the following single-point features are generally digitized as degenerate line elements, they are digitized as node elements when located on a line (200 - closure) collected in this category. 150 0300 Horizontal control station, third order or better, permanent mark This code identifies a degenerate line placed on a horizontal control station of third order or better with a permanent mark. It is shown by symbols 216(A), 512.99(C), or 2102.03(D). If the control station is coincident with a section corner as shown by symbols 229(A) or 512.101(C) also use code 159 0030. 150 0301 Horizontal and vertical control station, third order or better This code identifies a degenerate line placed on a horizontal control station having elevation data of third order or better and labeled BM (benchmark) as shown by symbols 217(A), 512.199(C), or 2102.03(D). If the control station is coincident with a section corner as shown by symbols 229(A) or 512.101(C) also use code 159 0030. See codes 153---- through 156---- for the appropriate elevation code. 150 0302 Horizontal control station, vertical angle bench mark (VABM) This code identifies a degenerate line placed on a horizontal control station, third order or better, with vertical angle elevation indicated by the label VABM as shown by symbols 218(A) or 2102.03(D). See codes 153---- through 156---- for the appropriate elevation code. 150 0303 Horizontal control station, checked spot elevation This code identifies a degenerate line placed on a horizontal control station, third order or better, with a checked spot elevation as shown by symbols 219(A), 512.99(C), or 2102.04(D). Do not code the elevation value in this category because it is coded in the hypsography category. 150 0310 Vertical control station, third order or better, tablet This code identifies a degenerate line that is placed on a vertical control station with elevation data of third order or better and that is marked with a tablet as is shown by symbols 220(A), 512.100(C), or 2102.06(D). If that station is coincident with a found section corner as shown by symbols 230(A) or 512.102(C), also use code 159 0030. See codes 153--- through 156- -- for the appropriate elevation code. 150 0311 Vertical control station, recoverable mark, third order or better, no tablet This code identifies a degenerate line placed on a vertical control station without a tablet but with a recoverable mark as shown by symbols 221(A), 512.100(C), or 2102.07(D). See codes 153---- through 156---- for the appropriate elevation code. 150 0320 Boundary monument, third order or better, tablet This code identifies a degenerate line placed on a boundary monument with elevation data of third order or better that has a tablet as shown by symbols 222, 501 (A) or 512.104, 523.22 (C). If the monument is shown by symbols 222(A) or 512.104(C) also use code 159 0009; if shown in red by symbols 501(A) or 523.11(C) also use code 159 0030. Although both of these symbols are digitized in another category, they must be digitized in this category as well to collect the elevation data. A monument number, if shown, is encoded in the Boundaries category. See codes 153 ---- through 156 ---- for the appropriate elevation code. 150 0321 Boundary monument, third order or better, no tablet This code identifies a degenerate line placed on a boundary monument with elevation data of third order or better but without a tablet as shown by symbols 223, 501 (A) or 512.104, 523.11 (C). If the monument is shown by symbols 223(A) or 512.104(C), also use code 159 0009; if shown in red by symbols 501(A) or 523.11(C), also use code 159 0030. A monument number, if shown, is encoded in the Boundaries category. See codes 153 ---- through 156 ---- for the appropriate elevation code. 150 0330 Reference monument This code identifies a degenerate line placed on a reference monument shown by symbols 226(A) or 512.105(C). 150 0331 U.S. mineral or location monument This code identifies a degenerate line placed on a U.S. mineral or location monument as shown by symbols 227(A), 512.106(C), or 2102.12(D). This is the only code in this category that appears on 1:100,000-scale maps where it is shown by symbol 112.46(B). 150 0332 Other control point This code identifies a degenerate line placed on any other control point as shown by symbols 231(A) or 512.103(C). 3.9.6 General Purpose Attribute Codes There are no general purpose attribute codes in this category. 3.9.7 Descriptive Attribute Codes There are nine attribute codes that are used to encode fractions of elevation values in tenths. 150 0601 .1 150 0602 .2 150 0603 .3 150 0604 .4 150 0605 .5 150 0606 .6 150 0607 .7 150 0608 .8 150 0609 .9 3.9.8 Parameter Attribute Codes 151 00-- State or State equivalent FIPS code Enter in the two spaces, flush right, the two digit FIPS code for the state in which the control point is located. 152 0--- County or county equivalent FIPS code Enter in the three spaces, flush right, the three-digit FIPS code for the county in which the control point is located. 153 ---- Elevation in feet Enter in the four spaces, flush right, the elevation shown for the control point, shown in feet on standard unit maps. If the elevation is greater than 9,999 feet use code 156 ----. 154 ---- Elevation in meters Enter in the four spaces, flush right, the elevation shown for the control point, shown in meters on metric unit maps. If a fractional part of a meter is shown, use the appropriate descriptive attribute to encode the value. 155 ---- Elevation in feet below datum Enter in the four spaces, flush right, the elevation shown for the control point. This code is only used for negative elevations shown in feet on standard unit maps. 156 ---- Elevation minus 10,000 for elevations greater than 9,999 feet If the elevation for a control point is greater than 9,999 feet, subtract 10,000 from that elevation and enter the remainder in the four spaces, flush right. Do not use this code with code 153 ---- to encode the total amount. 157 ---- Elevation in meters below datum Enter in the four spaces, flush right, the elevation shown for the control point. This code is only used for negative elevations shown in meters on metric unit maps. Examples: elevation 8,745 feet - 153 8745 elevation 12,321 feet - 156 2321 elevation 423 meters - 154 0423 elevation 3,480.5 feet - 153 3480, 150 0605 elevation -5 feet - 155 0005 159 00-- Coincident feature This code is defined in section 3.3.3. (Current version containing all changes through 11/15/93) 3.10 TRANSPORTATION--MAJOR CODES 170, 180, 190 The National Mapping Division collects digital information about transportation in three categories to support the analysis and extraction of data to meet the needs of a wide variety of users. The categories collected are: major code 170 - Roads and Trails major code 180 - Railroads major code 190 - Pipelines, Transmission Lines, and Miscellaneous Transportation Features 3.10.1 General Principles These data are collected in three separate categories for each map source, which means that the attribute codes from the three categories are not intermingled, however the three categories are distributed by the National Cartographic Data Base Office as one unit. When collection of transportation is authorized from a map source, all of the transportation for that source is collected. If there are no features in a particular category on a source, the header record shows that the file was initialized to hold Roads and Trails, Railroads, or Pipelines, Transmission Lines, and Miscellaneous Transportation Features, but the neatlines of the source, the background area, and the area outside the map, are the only information digitized for that category. The only area records in any transportation category are one or more background areas, existing void areas, and the area outside the map. The general purpose attribute codes that are used on various element types are applicable only to nodes and lines. The descriptive attribute codes are used as modifiers to the node, line, degenerate line, or general purpose attribute code that defines the feature. The common attribute codes described in section 3.3.3 are used in this category. In general, if multiple attributes are needed to describe a feature the ordering is not significant. An exception occurs in coding highway route numbers. If a highway is labeled BYP, ALT, BR, and so on, then the route number parameter code should be preceded by the appropriate descriptive code for Bypass, Alternate, or Business, and so on. This is especially important if multiple descriptive codes are required to describe a road, so that the descriptive code may be associated with the proper route number. 3.10.1.1 Transportation The attribute codes authorized for use in digitizing Transportation are in sections 3.10.1.2 through 3.10.1.4. The instructions for use of the attribute codes are in sections 3.10.2 through 3.10.4. 3.10.1.2 Roads and Trails - Major Code 170 o Node attribute codes 170 0001 Bridge abutment 170 0002 Tunnel portal 170 0004 Gate 170 0005 Cul-de-sac 170 0006 Dead end 170 0007 Drawbridge o Area attribute codes 000 0000 Outside area 170 0100 Void area o Line attribute codes 170 0201 Primary route, class 1, symbol undivided 170 0202 Primary route, class 1, symbol divided by centerline 170 0203 Primary route, class 1, divided, lanes separated 170 0204 Primary route, class 1, one way, other than divided highway 170 0205 Secondary route, class 2, symbol undivided 170 0206 Secondary route, class 2, symbol divided by centerline 170 0207 Secondary route, class 2, divided, lanes separated 170 0208 Secondary route, class 2, one way, other than divided highway 170 0209 Road or street, class 3 170 0210 Road or street, class 4 170 0211 Trail, class 5, other than four-wheel-drive vehicle 170 0212 Trail, class 5, four-wheel-drive vehicle 170 0213 Footbridge 170 0214 Road ferry crossing 170 0215 Perimeter of parking area 170 0216 Arbitrary line extension 170 0217 Road or street, class 3, symbol divided by centerline 170 0218 Road or street, class 3, divided, lanes separated 170 0219 Road or street, class 4, one way 170 0220 Closure line 170 0221 Road or street, class 3, one way 170 0222 Road in transition 170 0299 Processing line o Single-point attribute codes None o General purpose attribute codes - node or line 170 0401 Traffic circle 170 0402 Cloverleaf or interchange 170 0403 Tollgate, toll plaza, or perimeter of toll plaza 170 0404 Weigh station 170 0405 Nonstandard section of road o Descriptive attribute codes 170 0601 In tunnel 170 0602 Overpassing, on bridge 170 0603 Under construction, classification known 170 0604 Under construction, classification unknown 170 0605 Labeled "old railroad grade" 170 0606 Submerged or in ford 170 0607 Underpassing 170 0609 Toll road 170 0610 Privately operated or restricted use 170 0611 Proposed 170 0612 Double-decked 170 0613 In service facility, rest area, or roadside park 170 0614 Elevated 170 0615 Bypass route 170 0616 Alternate route 170 0617 Business route 170 0618 On drawbridge 170 0619 Spur 170 0620 Loop 170 0621 Connector 170 0622 Truck route 170 0623 With railroad 170 0624 Covered 170 0650 Road width 46-55 feet, 0.025 inch at 1:24,000 170 0651 Road width 56-65 feet, 0.030 inch at 1:24,000 170 0652 Road width 66-75 feet, 0.035 inch at 1:24,000 170 0653 Road width 76-85 feet, 0.040 inch at 1:24,000 170 0654 Road width 86-95 feet, 0.045 inch at 1:24,000 170 0655 Road width 96-105 feet, 0.050 inch at 1:24,000 170 0656 Road width 106-115 feet, 0.055 inch at 1:24,000 170 0657 Road width 116-125 feet, 0.060 inch at 1:24,000 170 0658 Road width 126-135 feet, 0.065 inch at 1:24,000 170 0659 Road width 136-145 feet, 0.070 inch at 1:24,000 o Parameter attribute codes 170 0000 Photorevised feature 171 ---- Number of lanes 172 ---- Interstate route number 173 ---- U.S. route number 174 ---- State route number 175 ---- Reservation, park, or military route number 176 ---- County route 177 XXYY Alphabetic portion of any route number Substitute numeric equivalent of alphabetic portion for XX and for YY as follows: 00 = blank, 01 = A, 02 = B, 03 = C, 04 = D, 05 = E, 06 = F, 07 = G, 08 = H, 09 = I, 10 = J, 11 = K, 12 = L, 13 = M, 14 = N, 15 = O, 16 = P, 17 = Q, 18 = R, 19 = S, 20 = T, 21 = U, 22 = V, 23 = W, 24 = X, 25 = Y, 26 = Z. 178 0000 Best estimate of position or classification 179 00-- Coincident feature 3.10.1.3 Railroads - Major Code 180 o Node attribute codes 180 0001 Bridge abutment 180 0002 Tunnel portal 180 0007 Drawbridge o Area attribute codes 000 0000 Outside area 180 0100 Void area o Line attribute codes 180 0201 Railroad 180 0202 Railroad in street or road 180 0204 Carline 180 0205 Cog railroad, incline railway, or logging tram 180 0207 Railroad ferry crossing 180 0208 Railroad siding or spur 180 0209 Perimeter or limit of yard 180 0210 Arbitrary line extension 180 0211 Closure line 180 0299 Processing line o Single-point attribute codes None o General purpose attribute codes - node, line, or degenerate line 180 0400 Railroad station, perimeter of station 180 0401 Turntable 180 0402 Roundhouse o Descriptive attribute codes 180 0601 In tunnel 180 0602 Overpassing, on bridge 180 0603 Abandoned 180 0604 Dismantled 180 0605 Underpassing 180 0606 Narrow gauge 180 0607 In snowshed or under structure 180 0608 Under construction 180 0609 Elevated 180 0610 Rapid transit 180 0611 On drawbridge 180 0612 Private 180 0613 U.S. Government 180 0614 Juxtaposition o Parameter attribute codes 180 0000 Photorevised feature 181 ---- Number of tracks 188 0000 Best estimate of position or classification 189 00-- Coincident feature 3.10.1.4 Pipelines, Transmission Lines, and Miscellaneous Transportation Features - Major Code 190 o Node attribute codes 190 0001 End of transmission line at power station, substation, or hydroelectric plant 190 0002 End of pipeline at oil or gas field 190 0003 End of pipeline at refinery, depot, or tank farm 190 0004 Steel or concrete tower on transmission line o Area attribute codes 000 0000 Outside area 190 0100 Void area o Line attribute codes 190 0201 Pipeline 190 0202 Power transmission line 190 0203 Telephone or telegraph line 190 0204 Aerial tramway, monorail, or ski lift 190 0205 Arbitrary line extension 190 0206 Closure line 190 0299 Processing line o Single-point attribute codes None o General purpose attribute codes - node, line, or degenerate line 190 0400 Power station 190 0401 Substation 190 0402 Hydroelectric plant 190 0403 Landing strip, airport, or perimeter of airport 190 0404 Heliport, perimeter of heliport 190 0405 Launch complex, perimeter of launch complex 190 0406 Pumping station or compressor station 190 0407 Seaplane ramp or landing area 190 0408 Measuring station, or valve station o Descriptive attribute codes 190 0600 Underground 190 0601 Under construction 190 0602 Abandoned 190 0603 Above ground 190 0604 Labeled "closed" 190 0605 Unimproved, loose surface 190 0606 Submerged 190 0607 Nuclear o Parameter attribute codes 190 0000 Photorevised feature 198 0000 Best estimate of position or classification 199 00-- Coincident feature 3.10.2 Instructions for the Use of Attribute Codes for Roads and Trails 3.10.2.1 Node Attribute Codes 170 0001 Bridge abutment This code identifies a node placed on the central point of a wing tick that indicates either end of a bridge. The wing ticks are shown by symbols 137, 138, 146 (A); 112.83, 116.6 (B); 511.15(C); or 2105.01, 2105.02 (D). 170 0002 Tunnel portal This code identifies a node placed at the point of a wing tick that indicates either end of a road tunnel. The tunnel portal is indicated by symbols 139(A), 112.83(B), 511.17(C), or 2105.03(D). See code 170 0601 for coding the tunnel. 170 0004 Gate This code identifies a node placed on a tick line labeled "gate," other than a tollgate, that appears at the beginning of a controlled public access road. The feature is shown on standard quadrangles by the same tick as symbols 104(A) or 2103.06(D) although the label is different. This code does not apply to 1:100,000-scale maps. 170 0005 Cul-de-sac This code identifies a cul-de-sac shown by symbols 116.10, 121.10 (B); 511.29, 516.7 (C); or 2103.09(D). The symbol may be digitized as a node or a line. When a cul-de-sac is less than or equal to 0.030 inch in diameter, it is digi-tized as a node and assigned this code. When the feature is greater than 0.030 inch in diameter and does not have an interior island, it is digitized as a line. An unattributed node is placed at the end of the road, and a line is digi-tized around the perimeter of the cul-de-sac and identified by this code and the appropriate road classification. When the cul-de-sac is shown with an interior island, the road that forms the cul-de-sac is digitized and coded as appropriate for the road class and is not identified by this code. 170 0006 Dead end This code identifies a dead-end street that has been closed with a tick as in symbols 116(A), 511.21, 511.22 (C), or 2105.07(D). This code does not apply to 1:100,000-scale maps. 170 0007 Drawbridge This code identifies a node that is digitized in the center of the circle portion of the drawbridge symbol: 138(A), 511.15, 516.11 (C), or 2105.02(D). See code 170 0618 for coding the road segments on both sides of the circle portion of the drawbridge symbol. This code does not apply to 1:100,000-scale maps. 3.10.2.2 Area Attribute Codes 000 0000 Outside area This code is described in section 3.3.3. 170 0100 Void area This code identifies an area on the source material where no roads and trails data exist because of replacement by imagery or a pattern from another category. A void area is also found beyond the national boundary to distinguish it from the background area. Where appropriate, the perimeter of the void area, usually a closure line, is coded as coincident with the category that defines the roads and trails void area. The closure line that defines the void area beyond the national boundary is coded as coincident with the Boundaries category (179 0009). 3.10.2.3 Line Attribute Codes 170 0201 Primary route, class 1, symbol undivided This code identifies a centerline digitized along a class 1 highway that has no division indicated. It is used for symbols 100, 101 (A), 121.1(B), or 511.10(C). It is also used for symbol 104(A) when that symbol is scribed as shown, that is, without a dividing line. It is also used for symbol 2103.01(D) when labeled as an interstate or U.S. Highway. Also use the appropriate width code (see codes 170 0650 through 170 0659). 170 0202 Primary route, class 1, symbol divided by centerline This code identifies the centerline digitized along a dual highway that is shown with three road casings. If the road exceeds the standard width for the map scale, add the appropriate road width code. It is used when symbol 100(A) is shown with the centerline division as is seen in symbols 109(A) or 511.11(C). It is also used for symbol 2103.02(D) when labeled as an interstate or U.S. Highway. This code does not apply to 1:100,000-scale maps. 170 0203 Primary route, class 1, divided, lanes separated This code describes a centerline digitized in each lane of a divided highway for which the lanes are separated by a median strip. If the road exceeds the standard width for the map scale, add the appropriate road width code. This code is used on symbols 110(A) or 511.11(C). The code is also used on symbol 121.1(B) when the road is separated into two lanes as described in the remarks block of that symbol. It is used for symbol 2103.02(D) when a median strip is shown on roads labeled as an Interstate or U.S. Highway. 170 0204 Primary route, class 1, one-way, other than divided highway This code describes a centerline digitized in a class 1 road that is designated for one-way traffic by the placement of a directional arrow, but is not part of a divided highway. This situation usually occurs in urban areas in which major through streets may be designated as one-way and are shown by symbols 100, 101 (A), 121.1(B), or 511.10(C). It is also used for symbol 2103.01(D) when labeled as an interstate or U.S. highway and designated for one-way traffic. Although one-way streets are not explicitly symbolized on 1:100,000-scale maps, this code is applied to a centerline digitized in a class 1 road that is clearly one-directional. 170 0205 Secondary route, class 2, symbol undivided This code describes a centerline digitized in a class 2 road symbol that has no division of lanes indicated. It is used for symbols 102, 103 (A), 121.2(B), or 511.10(C). This code is also used for symbol 2103.01(D) when labeled as a State or county highway. (State highways depicted by this symbol also require the best estimate code, 178 0000.) 170 0206 Secondary route, class 2, symbol divided by centerline This code describes a centerline digitized in a second class dual highway shown with three road casings as in symbols 109(A) or 511.11(C). This code is also used for symbol 2103.02(D) when labeled as a State or county highway. (State highways depicted by this symbol also require the best estimate code, 178 0000.) This code does not apply to 1:100,000-scale maps. 170 0207 Secondary route, class 2, symbol divided, lanes separated This code describes a centerline digitized in each lane of a class 2 highway that is shown with lanes separated by a median strip as in symbols 110(A) or 511.11(C), but with the dashed fill as in symbol 514(A). On 1:100,000-scale maps, the code identifies each lane of highway as shown in symbol 121.2(B). It is also used for symbol 2103.02(D) when labeled as a State or county highway. (State highways also use the best estimate code, 178 0000.) 170 0208 Secondary route, class 2, one way, other than divided highway This code describes a centerline digitized in a class 2 highway that is designated as one way by a directional arrow but is not part of a divided highway. This generally occurs only in urban areas. It is used for symbol 2130.01(D) when labeled as a State or county highway and designated for one-way traffic. (State highways also use the best estimate code, 178 0000.) Although one-way streets are not explicitly symbolized on 1:100,000-scale maps, this code is applied to a centerline digitized in a class 2 road that is clearly one-directional. 170 0209 Road or street, class 3 This code describes a centerline digitized in a class 3 road or street shown by symbols 105(A), 116.1(B), or 516.1(C). It is also used for symbol 2103.01(D) when unlabeled as to administrative responsibility. 170 0210 Road or street, class 4 This code describes a centerline digitized in a class 4 road or street shown by symbols 106(A), 116.2(B), 516.4(C), or 2103.11(D). This code is also used for street patterns in built-up areas on 1:100,000-scale maps shown by symbol 116.7(B). 170 0211 Trail, class 5, other than four-wheel drive This code describes a line digitized along a class 5 trail symbol that is not designated for four-wheel-drive use. The trail symbol may be labeled in various ways such as "foot trail," "pack trail," "bicycle trail," or "old railroad grade." (Also see code 170 0605) This code is used for symbols 107, 133 (A), 116.3(B), 516.5(C), or 2103.12(D). 170 0212 Trail, class 5, four-wheel drive This code describes a line digitized along a class 5 trail that is labeled "Jeep" or "4WD". It is used on symbols 107(A), 116.3(B), 516.5(C), or 2103.12(D). 170 0213 Footbridge This code describes a line digitized along a footbridge shown by symbols 140(A), 511.23(C), or 2105.04(D). The footbridge is digitized even when the connecting footpaths are not shown. The nodes that indicate the ends of the footbridge are not given an attribute code. This code does not apply to 1:100,000-scale maps. 170 0214 Road ferry crossing This code describes a line digitized from bank to bank along a ferry crossing route as shown in symbols 150, 151 (A), 112.84(B), 511.24(C), or 2105.09(D). 170 0215 Perimeter of parking area This code describes a line digitized along the perimeter of an area usually labeled "parking area" and shown by symbol 511.25(C). Many parking areas are not labeled, but are obvious because of their shape and proximity to such features as retail centers and stadiums. The limits of the parking area may be shown by a road symbol in which case the appropriate road code classification is used as well. If the perimeter is shown by a cleared area then the apparent limit of the parking area carries this code alone. This code does not apply to 1:100,000-scale maps. 170 0216 Arbitrary line extension This code is used on a portion of a linear feature that is not symbolized, but is required for connectivity of the feature, for example, a line digitized to join portions of a road that is broken for an underpass, as shown in symbols 145, 146 (A); 116.4, 116.7 (B); 516.10(C); and 2105.06(D). Road classes and route numbers are also encoded on this line as appropriate. 170 0217 Road or street, class 3, symbol divided by centerline This code describes a centerline digitized in a class 3 road or street that is shown with three road casings to indicate that it is divided as is shown in symbol 109(A) but without any red fill. It is also used for symbol 2103.02(D) when unlabeled as to administrative responsibility. This code does not apply to 1:100,000-scale maps. 170 0218 Road or street, class 3, divided, lanes separated This code describes a centerline digitized in each lane of a class 3 road or street that is shown with lanes separated by a median strip as in symbols 110(A) or 516.2(C), but without any red fill. It is also used for symbol 2103.02(D) when unlabeled as to administrative responsibility. This code does not apply to 1:100,000-scale maps. 170 0219 Road or street, class 4, one way This code describes a centerline digitized in a class 4 road that is designated as one way by a directional arrow. A class 4 road is shown by symbols 106(A), 116.2(B), 516.4(C), or 2103.11(D). 170 0220 Closure line This code identifies a line segment digitized to define the extent of an areal feature, such as a void area, that is not otherwise explicitly symbolized. 170 0221 Road or street, class 3, one way This code identifies a centerline digitized in a class 3 road that is designated as one way by a directional arrow. A class 3 road is shown by symbols 105(A), 116.1(B), or 516.1(C). Use this code for symbols 2103.01 and 2103.02 (D) when unlabeled as to administrative responsibility and designated for one-way traffic. 170 0222 Road in transition This code identifies a centerline digitized in a section of any road where a change in the road width occurs, and the transitional section is equal to or greater than 0.25 inch in length. An unattributed node is placed at the beginning and end of the extent of the transitional segment. The road classification is assigned to the transitional segment of the road for connectivity. 170 0299 Processing line Some routines in the processing software (PROSYS) have limitations in the number of lines, nodes, or areas that can be processed. For example, an area may be associated with no more than 4,751 lines. This code describes a line or lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed. 3.10.2.4 Single-Point Attribute Codes There are no single-point feature attribute codes in this category. 3.10.2.5 General Purpose Attribute Codes - node or line 170 0401 Traffic circle This code describes the marked-off area at the center of a junction of roads (three or more) that forms a circle around which traffic normally moves in one direction (not to be confused with a cul-de-sac). If the diameter of the interior space in the circle is 0.030 inch or less the feature is digitized as a node at the intersection of the roads entering the circle. If the interior space is greater than 0.030 inch then the feature is digitized as a center-line that follows the circle and is broken by unattributed nodes at the points where the roads join the circle. Road classes and route numbers are also encoded on this centerline as appropriate. This code is used on symbols 114(A); 116.10, 121.10 (B); 511.28, 516.6 (C); or 2103.09(D). 170 0402 Cloverleaf or interchange This code describes an intersection of roads and ramps at a cloverleaf or interchange. If the cloverleaf is shown by symbol 115(A) at the symbol size shown, the feature is digitized as a node and described by this code. If the cloverleaf or interchange is shown to scale, or larger than symbol size as shown in symbols 121.5(B), 511.13, 516.8 (C), or 2103.10(D), then the feature is digitized by a line that follows the road and ramp pattern and is described by this code. A cloverleaf or interchange generally does not carry a road class or route number. 170 0403 Tollgate, toll plaza, or perimeter of toll plaza This code identifies a node placed at the center of a tick placed on a road to identify a tollgate. It is shown by symbols 104(A), 511.26(C), or 2103.06(D). It also identifies a line digitized around an area on a toll road that is labeled "toll plaza." If the exact extent of the plaza is difficult to determine also use code 178 0000. The centerline digitized for the road should be continued through the feature. 170 0404 Weigh station This code identifies a feature labeled "weigh station" or "Agricultural Inspection Station." On 1:100,000-scale maps the feature is shown by symbol 121.9(B) and digitized as a line. On 1:24,000-scale maps several treatments may be used depending on the size of the feature. If shown by a road or ramp only, digitize a line. If shown in a similar manner to a large toll plaza, digitize a line around the perimeter of the feature. If depicted by a located object symbol or building without ramps or roads shown, digitize as a degenerate line. 170 0405 Nonstandard section of road This code describes a line digitized on the casings of a nonstandard section of any class road normally symbolized by parallel road casings. An unattributed node is placed on the ends of the centerline digitized on either side of the nonstandard section of road, and the casings delineating the nonstandard section are digitized by using this code. A road classification or route number is not assigned to the lines digitized as nonstandard section of road. However, for connectivity, the road classification and route number (if applicable) are assigned to the digitized centerline of the standard section of the road that continues through the unattributed nodes. This description also applies to the nonstandard section of the road shown at a road junction, without an island, where it widens to 0.060 inch or more. When the nonstandard section of the road shown by a circle (not to be confused with the cul-de-sac or traffic circle) is 0.030 inch or less in diameter, a node is digitized in the center of the rounded section of the road and assigned this code. 3.10.2.6 Descriptive Attribute Codes 170 0601 In tunnel This code describes the portion of a road or trail that is shown as being in a tunnel by symbols 139(A); 121.7, 116.5 (B); 511.16, 511.17, 516.12 (C); or 2105.03(D). The code applies only to the portion between the wing ticks (see 170 0002 for coding the wing ticks). Also use the road classification code. 170 0602 Overpassing, on bridge (except drawbridge) This code describes the section of a road or trail that passes over, rather than intersects, another feature, such as when a road crosses over a river or railroad on a bridge. The code is applied only to the section of a feature that is raised to cross the obstruction. In some cases the relationship of the two features is more simply shown by coding the underpassing portion (see code 170 0607) because only one of the two conditions need be coded. It is used with symbols 137, 138, 146 (A); 116.6, 121.8 (B); 511.15, 516.11 (C), or 2105.01, 2105.02 (D). See code 170 0618 for treatment of a feature on a drawbridge. 170 0603 Under construction, classification known This code describes the portion of a road that is labelled "under construction" and the class of the road is known. It is used in conjunction with the code that describes the class of the road. The code is used on symbols 112(A), 511.12(C), or 2103.08(D), for which the red fill indicates the class of the road. On 1:100,000-scale maps only class 1 roads under construction are shown, therefore, this code is used only on symbol 121.3(B). The exact extent of the construction is not indicated on 1:100,000-scale maps. In such cases, apply the code to all sections of the road, extending from the label in both directions, until an intersection with another road or the edge of an urban tint provides a reasonable limit to the portion of the road considered to be under construction. 170 0604 Under construction, classification unknown This code describes a road labeled "under construction" for which the classification is unknown. The code is used on symbols 113(A) or 2103.08(D). This code is not used on 1:100,000-scale maps. 170 0605 Labeled "old railroad grade" This code describes a trail that follows the alignment of a dismantled railroad and is labeled "old railroad grade." The code is used on symbols 133(A), 116.3(B), 516.5(C), or 2104.12(D), in conjunction with 170 0211. No code from the railroad subcategory is used on this feature. 170 0606 Submerged or in ford This code describes the portion of a road or trail that fords a stream. The code is used on symbols 147, 148, 149 (A); 516.13(C); or 2105.08(D). In the case of a ford through a single-line stream, the code is applied to a node placed at the point where the road or trail intersects the stream. This code is not used on 1:100,000-scale maps. 170 0607 Underpassing This code describes the section of a road or trail that passes under, rather than intersects, another feature, as when a road crosses under another road that is on an overpass. The code is applied only to the underpassing portion of a longer feature or to the section of a feature that is broken to pass under an obstruction. In some cases the relationship of the two features is more simply shown by coding the overpassing portion (see code 170 0602) because only one of the two conditions need be coded. This code is used with symbols 145(A); 116.4, 121.6 (B); 511.14, 516.10 (C); or 2105.06(D). 170 0609 Toll This code describes a road that is labeled "toll road." It is used on symbols 104(A), 121.1(B), or 2103.06(D). 170 0610 Privately operated or restricted use This code describes a road or trail that is restricted, such as a road through a military reservation, a road or trail through a ranch, or a fire road in a forest preserve. These roads are labeled "private" or "restricted" and may have a gate shown at the point where the restriction begins. This code also describes a road or trail that is not labeled but is only accessible by way of a road labeled "private" or "restricted." 170 0611 Proposed This code describes a road that has been planned and sufficient information was available to show the proposed location on the map. Such a road is shown by symbols 516(A) or 521.3(C) and is labeled "proposed location." This code is not used on 1:100,000-scale maps. 170 0612 Double-decked This code describes a road that is constructed over another road or a road on a two-level bridge. The double-decked structure is shown by the standard road symbol appropriate to its class, symbol 2103.03(D), and is labeled "double-decked." This code is not used on 1:100,000-scale maps. 170 0613 In service facility, rest area, or roadside park This code identifies a road that runs through a service facility or rest area. On 1:24,000- and 1:25,000-scale maps the facility is labeled "service facility," "service area," "service plaza," "rest area" or "roadside park," shown by symbols 511.18 or 516.9(C). No specific symbol is shown in reference A. On 1:100,000-scale maps the facility is shown by symbols 116.8(B) or 121.9(B), scribed to scale. The service facility roads are usually distinguished by a different line weight from that of the main road and do not require a road class. 170 0614 Elevated This code describes a road that is labeled "elevated" to indicate that it is raised above ground level. This code is not used on bridges. (See 170 0602) 170 0615 Bypass This code describes a road that is identified as a bypass route by the presence of the letters "BYP" in the highway route marker. This code is used in addition to and precedes the parameter code that contains the route number. 170 0616 Alternate This code describes a road that is identified as an alternate route by the presence of the letters "ALT" in the highway route marker. This code is used in addition to and precedes the parameter code that contains the route number. 170 0617 Business This code describes a road that is identified as a business route by the presence of the letters "BR" in the highway route marker. This code is used in addition to and precedes the parameter code that contains the route number. 170 0618 On drawbridge This code describes a centerline digitized along the portion of a road that crosses an obstruction, usually a water area, on a drawbridge shown by symbols 138(A) or 2105.02(D). See code 170 0007 for coding the circular portion of the drawbridge symbol. This code does not apply to 1:100,000- scale maps. 170 0619 Spur This code identifies a road that is described as a spur route by the presence of the word "Spur" in the highway route marker. This code is used in addition to and precedes the parameter code that contains the route number. 170 0620 Loop This code identifies a road that is described as a loop route by the presence of the word "Loop" in the highway route marker. This code is used in addition to and precedes the parameter code that contains the route number. 170 0621 Connector This code identifies a road that is described as a connector route by the presence of the word "Conn" in the highway route marker. This code is used in addition to and precedes the parameter code that contains the route number. 170 0622 Truck route This code identifies a road that is described as a truck route by the presence of the abbreviation "TR" in the highway route marker. This code is used in addition to and precedes the parameter code that contains the route number. 170 0623 With railroad This code describes a section of a road or street where the railroad is superimposed on the road as shown by symbols 124(A), 112.25(B), 512.08, 512.09 (C), or 2104.07(D). Also use the appropriate road classification code. Because the description indicates coincidence with a railroad, the coincident feature code is not required. 170 0624 Covered This code describes a feature that is labeled "covered." 170 0650 Road width 46-55 feet, 0.025 inch at 1:24,000 170 0651 Road width 56-65 feet, 0.030 inch at 1:24,000 170 0652 Road width 66-75 feet, 0.035 inch at 1:24,000 170 0653 Road width 76-85 feet, 0.040 inch at 1:24,000 170 0654 Road width 86-95 feet, 0.045 inch at 1:24,000 170 0655 Road width 96-105 feet, 0.050 inch at 1:24,000 170 0656 Road width 106-115 feet, 0.055 inch at 1:24,000 170 0657 Road width 116-125 feet, 0.060 inch at 1:24,000 170 0658 Road width 126-135 feet, 0.065 inch at 1:24,000 170 0659 Road width 136-145 feet, 0.070 inch at 1:24,000 The 10 codes listed above are used to describe a road that is scribed to scale rather than shown by the standard size symbol on 1:24,000-scale maps. This code is used in addition to the code that describes the class of the road. At 1:24,000-scale, roads greater than 40 feet and dual highways greater than 70 feet are scribed to scale. This code does not apply to 1:100,000- scale maps. 3.10.2.7 Parameter Attribute Codes 170 0000 Photorevised feature This code is described in section 3.3.3. 171 ---- Number of lanes This code is used to encode the number of lanes annotated on a road on the source map. The number of lanes is entered in the spaces, flush right, one to four digits. Use this code on all segments of a road to which the annotated number of lanes applies. 172 ---- Interstate route number This code is used to encode the route number of an interstate highway. Enter the number shown on the highway route marker in the spaces, flush right, one to four digits. If the route number contains alphabetic characters also use 177 XXYY. If the highway is labeled BYP, ALT, or BR, this parameter code should be preceded by the appropriate descriptive code, such as 170 0615, 170 0616, or 170 0617 respectively. Do not encode the uppercase "I" that is sometimes associated with an interstate highway, as this parameter code imparts that information. 173 ---- U.S. route number This code is used to encode the route number of a U.S. highway. Enter the number shown on the highway route marker in the spaces, flush right, one to four digits. If the route number contains alphabetic characters also use code 170 XXYY. If the highway is labeled BYP, ALT, or BR, this parameter code, should be preceded by the appropriate descriptive code, such as 170 0615, 170 0616, or 170 0617 respectively. Do not encode the uppercase "US" that is sometimes associated with a U.S. highway, as this parameter code imparts that information. 174 ---- State route number This code is used to encode the route number of a State highway. Enter the number shown on the highway route marker in the spaces, flush right, one to four digits. If the route number contains alphabetic characters also use code 177 XXYY. If the highway is labeled BYP, ALT, or BR, this parameter code, should be preceded by the appropriate descriptive code, such as 170 0615, 170 0616, or 170 0617 respectively. Do not encode the uppercase "SR" that is sometimes associated with a State highway, as this parameter code imparts that information. 175 ---- Reservation, park, or military route number This code is used to encode the route number of a reservation, park, or military route number. Enter the number shown on the highway route marker in the spaces, flush right, one to four digits. If the route number contains alphabetic characters also use code 177 XXYY. If the highway is labeled BYP, ALT, or BR, this parameter code, should be preceded by the appropriate descriptive code, such as 170 0615, 170 0616, or 170 0617 respectively. This code is not used on 1:100,000-scale maps. 176 ---- County route number This code is used to encode a county route number. Enter the number shown on the highway route marker in the spaces, flush right, one to four digits. If the route number contains alphabetic characters also use code 177 XXYY. If the highway is labeled BYP, ALT, or BR, this parameter code should be preceded by the appropriate descriptive code, such as 170 0615, 170 0616, or 170 0617 respectively. This code is not used on 1:100,000-scale maps. 177 XXYY Alphabetic portion of any route number This code is used to encode the alphabetic portion of any route number. The code is used in conjunction with the appropriate code, 172 ---- through 176 ----, if the route designation is mixed numeric and alphabetic. The code can hold one or two letters by substituting the numeric equivalent 01 to 26 for the letters A to Z with 00 substituting for a blank. If one letter is encoded it is entered in the YY portion of the code with blank coded into the XX portion. The code precedes or follows the numeric route code in accordance with its actual position. In the case of an entirely alphabetic route designator, also use the code to specify jurisdiction with 0000 entered into the minor code. Examples: State Route B143 = 177 0002 174 0143 County Route 6R = 176 0006 177 0018 U.S. Route A1A = 177 0001 173 0001 177 0001 State Route KK = 177 1111 174 0000 Do not use this code to represent "ALT", "BR", "BYP", "I" (interstate), "SR" (state route), or "U.S." (United States) as these qualifiers of the route number are encoded by other codes. For example: Alternate U.S. route 1 would be coded 170 0616 173 0001. 178 0000 Best estimate of position or classification This code is described in section 3.3.3. 179 00-- Coincident feature This code is described in section 3.3.3. One example for this category is a road on a dam (shown by symbols 155(A), 112.65(B), or 2108.04(D)) that has the code 179 0005 assigned to it, in addition to the codes that describe the road. 3.10.3 Instructions for the Use of Attribute Codes for Railroads 3.10.3.1 Node Attribute Codes 180 0001 Bridge abutment This code describes a node placed on the central point of a wing tick that indicates either end of a railroad bridge. The wing ticks are shown by symbols 141, 142, 143 (A); 112.17(B); 512.21(C); or 2105.02, 2105.05 (D). For any symbol in which the tick is represented by two lines meeting at an acute angle, the node is placed at the point. For any symbol in which the tick is represented by two lines meeting a third line at obtuse angles, the node is centered on the middle line. 180 0002 Tunnel portal This code identifies a node placed at the point of a wing tick that indicates either end of a railroad tunnel. The tunnel portal is indicated by symbols 144(A), 112.19(B), 512.21(C), or 2105.03(D). 180 0007 Drawbridge This code identifies a node that is digitized in the center of the circle portion of the drawbridge shown by symbols: 143(A), 512.21(C), or 2105.02(D). See code 180 0611 for coding the railroad segments on both sides of the circle portion of the drawbridge symbol. This code does not apply to 1:100,000-scale maps. 3.10.3.2 Area Attribute Codes 000 0000 Outside area This code is described in section 3.3.3. 180 0100 Void area This code identifies an area on the source material where no railroad data exist because of replacement by imagery or a pattern from another category. A void area is also found beyond the national boundary to distinguish it from the background area. Where appropriate, the perimeter of the void area, usually a closure line, is coded as coincident with the category whose pattern defines the void area. The closure line that defines the void area beyond the national boundary is coded as coincident with the Boundaries category (189 0009). 3.10.3.3 Line Attribute Codes 180 0201 Railroad This code describes a railroad line shown by symbols 117 through 123, 127 through 130 (A); 112.11 through 112.14 (B); 512.1 through 512.5, 512.10 through 512.13 (C); or 2104.01 through 2104.06, 2104.10, 2104.11 (D). Unless qualified by a descriptive or parameter code, this code indicates a single-track, standard-gauge operating railroad line. If the symbol denotes a multiple-track railroad line, the centerline of the symbol is digitized by using this code as well as the appropriate parameter code to indicate the number of tracks. 180 0202 Railroad in street This code describes a railroad located on a street. It is shown by symbols 124(A), 112.25(B), 512.8, 512.9 (C), or 2104.07(D), where the street symbol is superimposed on the railroad symbol. Because the definition of this code indicates coincidence with a street, the coincident feature code is not used in this case. 180 0204 Carline This code describes a carline shown by symbols 131, 132, 133 (A); 112.27(B); or 512.14, 512.15 (C). If the feature is labeled as "abandoned," "dismantled," and so on, use the appropriate descriptive code in addition to this code. This code does not apply to provisional edition maps. 180 0205 Cog railroad, incline railway, or logging tram This code describes a special purpose railroad such as a cog railroad, incline railway, or logging tram as shown by symbols 188(A), 112.23(B), 512.24(C), or 2110.02(D). If the feature is labeled "abandoned," "dismantled," and so on, use the appropriate descriptive code in addition to this code. 180 0207 Railroad ferry crossing This code describes a line digitized from bank to bank along a ferry crossing route as shown in symbols 150(A), 112.21(B), 512.23(C), or 2105.09(D). 180 0208 Railroad siding, or spur This code describes a railroad siding that is one or more single tracks branching off from a main line of a railroad and shown by symbols 126(A), 112.16(B), 512.7(C), or 2104.09(D). This code also describes a spur that is single track that diverges from the main track and leads to some facility such as an industrial point. In both references the siding or spur is shown with a line weight of 0.003 inch to distinguish it from the main line, which is shown by a line weight of 0.005 inch. A railroad siding or spur may be of any length. 180 0209 Perimeter or limit of yard A railroad yard as shown in symbols 125(A), 112.15(B), 512.6(C), or 2104.08(D) is mapped to scale with the main line through the yard and the outermost tracks that form the perimeter shown in true position. The rest of the tracks in the yard are shown by a representative pattern. Therefore the outline of the yard is digitized as a line, by following the outermost tracks, given this code. The open end of the yard is closed off by a digitized line given this code and the code 180 0210. The main line is digitized and described by the appropriate railroad code where it can be distinguished. Large railroad yards may have interior islands or clear areas, that are not occupied by the track pattern. These area limits are digitized as a line by following the innermost track and identified with this code. 180 0210 Arbitrary line extension This code is used on a portion of a linear feature that is not symbolized; for example, this code may be used to identify a line digitized to complete or join portions of linear features, as in the underpass shown in symbols 145(A), 512.20(C), or 2105.06(D). This code is used in addition to the primary code. 180 0211 Closure line This code identifies a line segment digitized to define the extent of an areal feature, such as a void area, that is not otherwise explicitly symbolized. 180 0299 Processing line Some routines in the processing software (PROSYS) have limitations on the number of lines, nodes, or areas that can be processed. For example, an area may be associated with no more than 4,751 lines. This code describes the line or lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed. 3.10.3.4 Single-Point Attribute Codes There are no single-point attribute codes in this category. 3.10.3.5 General Purpose Attribute Codes - node, line, or degenerate line 180 0400 Railroad station, perimeter of station This code is used to describe a structure labeled railroad station. If the station is shown by symbols 136(A), 112.18(B), 512.18(C), or 2104.14(D), the station is digitized as a node on the line that represents the railroad. If the structure is less than 0.030 inch and separated by a gap in the line, it is digitized as a degenerate line. If the station is shown to scale, then a line is digitized that defines the perimeter of the station and is assigned this code. 180 0401 Turntable This code is used to describe a railroad turntable. If the turntable is shown by symbols 134(A), 512.17(C), or 2104.13(D) and is 0.06 inch in diameter, it is digitized as a node on the railroad line. If the turntable is shown to scale then it is digitized as a line that defines the circumference of the turntable. This code is not used on 1:100,000-scale sources. 180 0402 Roundhouse This code is used to describe a railroad roundhouse as shown by symbols 135(A), 112.22(B), 512.16(C), or 2104.13(D). Digitize a line that defines the perimeter of the roundhouse and give it this code. 3.10.3.6 Descriptive Attribute Codes 180 0601 In tunnel This code describes the portion of a railroad that is shown as being in a tunnel by symbols 144(A), 112.19(B), 512.22(C), or 2105.03(D). The code applies only to the portion of the railroad feature between the wing ticks. The code is used in addition to the codes that describe the railroad type. 180 0602 Overpassing, on bridge (except drawbridge) This code describes the section of a railroad that passes over, rather than intersects, another feature, as when a railroad crosses over a river or a road on a bridge. The code is applied only to the section of a feature that is raised to cross an obstruction. In some cases the relationship of the two features is more simply shown by coding the underpassing portion (see code 180 0605) because only one of the two conditions need be coded. It is used with symbols 141, 142, 143 (A); 112.17(B); 512.21(C); or 2105.02, 2105.05 (D). See code 180 0611 for treatment of a feature on a drawbridge. 180 0603 Abandoned This code is used to describe any railroad that is labeled "abandoned." An abandoned railroad is one for which the tracks and roadbed are still in place, although unused and of varying conditions. It is used with symbol 112.24(B). 180 0604 Dismantled This code describes a railroad that is labeled "dismantled." The term dismantled means that the tracks have been removed. Many railroads that are dismantled are labeled "old railroad grade" and are used and symbolized as trails on the Roads and Trails subcategory. These trails are not to be collected in the Railroad subcategory. Only features actually labeled "dismantled" are to be collected as a railroad feature, such as dismantled logging trams. 180 0605 Underpassing This code describes the section of a railroad that passes under, rather than intersects, another feature, as when a railroad crosses under a road that is on an overpass. The code is applied only to the underpassing portion of a longer feature or to the section of a feature that is broken to pass under an obstruction. In some cases the relationship of the two features is more simply shown by coding the overpassing portion (see code 180 0602) because only one of the two conditions need be coded. It is used with symbols 145(A), 112.20(B), 512.20(C), or 2105.06(D). 180 0606 Narrow gauge This code is used to describe any railroad that is shown by symbols 127 through 130 (A); 112.13, 112.14 (B); 512.10 through 512.13 (C); or 2104.10, 2104.11 (D). This code is used in addition to the line code that defines the feature as a railroad. 180 0607 In snowshed or under structure This code is used to describe any portion of a railroad that is shown with a snowshed as in symbols 177(A), 112.26(B), 512.19(C), or 2106.06 (D) or that is shown as running through a building in the same way. The railroad in the snowshed or building is digitized as a centerline in the symbol, and the building is collected in the manmade features category. 180 0608 Under construction This code is used to describe any feature that is labeled "under construction." 180 0609 Elevated This code is used to describe any feature that is labeled "elevated." 180 0610 Rapid transit Rapid transit railroad lines are shown by the standard railroad symbol appropriate to the feature but, in addition, are labeled "rapid transit." This code is used to describe symbols 117, 120 (A); 112.11, 112.12 (B); or 2104.01, 2104.04 (D), when labeled "rapid transit." 180 0611 On drawbridge This code describes the portion of a railroad that crosses an obstruction, usually water, on a drawbridge shown by symbols 143(A), 512.21(C), or 2105.02(D). This code does not apply to 1:100,000-scale maps. The digitized railroad on drawbridge is divided by a node placed in the circular portion of the drawbridge symbol and coded with code 180 0007. 180 0612 Private This code describes a railroad labeled "private." 180 0613 U.S. Government This code describes a railroad labeled as belonging to the U.S. Government. 180 0614 Juxtaposition This code describes a railroad shown by symbol 123(A) or 2104.06(D). The juxtaposition of railroad tracks outside of a railroad yard indicates that more than one railroad company shares the roadbed. Each railroad is digitized as described under "Railroad" (180 0201) and this code is used on each line of the railroad digitized. On 1:100,000-scale maps a similar treatment is used to indicate juxtaposition. 3.10.3.7 Parameter Attribute Codes 180 0000 Photorevised feature This code is described in section 3.3.3. 181 ---- Number of tracks This code is used to encode the number of tracks for a multiple track railroad as shown in symbols 121 through 123 (A); 512.3, 512.4 (B); 112.12(C); or 2104.4(D). The number of tracks is entered in the spaces, flush right, one to four digits. Use this code on all segments of a railroad to which the track number applies. Do not attempt to encode the number of tracks shown in railroad yards. 188 0000 Best estimate of position or classification This code is described in section 3.3.3. 189 00-- Coincident feature This code is described in section 3.3.3. 3.10.4 Instructions for the Use of Attribute Codes for Pipelines, Transmission Lines, and Miscellaneous Transportation Features 3.10.4.1 Node Attribute Codes 190 0001 End of transmission line at power station, substation, or hydroelectric plant This code describes a node placed at the end of a transmission line that terminates at a power station, substation, or power plant. Do not use this code when the termination point is not identified. 190 0002 End of pipeline at oil or gas field This code describes a node placed at the end of a pipeline that terminates at an oil or gas field. The code is used only when the area that is labeled oil field or gas field is not separated from the termination point by any other feature. 190 0003 End of pipeline at refinery, depot, or tank farm This code describes a node placed at the end of a pipeline that terminates at a labeled refinery or depot. It is also used when the pipeline terminates at a group of tanks that make up a tank farm, whether labeled or not. 190 0004 Steel or concrete tower on transmission line This code describes a node placed on a steel or concrete tower, that is located on a transmission line, shown by an open square as in symbols 512.91(C) and 2110.01(D). 3.10.4.2 Area Attribute Codes 000 0000 Outside area This code is described in section 3.3.3. 190 0100 Void area This code identifies an area on the source material where no miscellaneous transportation data exist because of replacement by imagery or a pattern from another category. A void area is also found beyond the national boundary to distinguish it from the background area. Where appropriate, the perimeter of the void area, usually a closure line, is coded as coincident with the category whose pattern defines the void area. The closure line that defines the void area beyond the national boundary is coded as coincident with the Boundaries category (199 0009). 3.10.4.3 Line Attribute Codes 190 0201 Pipeline This code describes a pipeline that is shown by symbols 190, 191 (A); 112.57, 112.58 (B); 512.93, 512.94, 516.23 (C); or 2110.04(D). When shown by symbols 190(A), 512.94(C), or the first illustration for 112.58(B), this code is used alone. When the pipeline is shown by symbols 191(A), 112.57(B), or 512.93(C), which indicates that it is above ground, then use the descriptive code 190 0603 in addition to this code. When the pipeline is submerged as shown in the illustration for symbols 116.12(B) or 512.94, 516.23 (C), also use the descriptive code 190 0606. 190 0202 Power transmission line This code describes a power transmission line that is shown by symbols 187(A), 112.55(B), 512.91(C), or 2110.01(D). The steel or concrete towers are digitized as attributed nodes (see code 190 0004). If an underground power line is shown and labeled "underground," then use the descriptive code 190 0600 in addition to this code. 190 0203 Telephone or telegraph line This code is used to describe a telephone or telegraph line shown by symbols 189(A), 112.54(B), 512.90(C), or 2110.03(D). These symbols are labeled "telephone" or "telegraph," but for coding purposes, no distinction is made between telephone and telegraph lines. 190 0204 Aerial tramway, monorail, or ski lift This code describes an aerial tramway, monorail, or ski lift shown by symbols 188(A), 112.59(B), 512.95(C), or 2110.02(D) and labeled as to type. 190 0205 Arbitrary line extension This code describes an arbitrary line that is not symbolized on the map but is digitized to link component symbolized features into pipeline or transmission line networks. For example, a power generating station located on the opposite side of a road from its associated transmission lines should be connected by a digitized line and given this code. This code is used in addition to the primary code. 190 0206 Closure line This code identifies a line segment digitized to define the extent of an areal feature, such as a void area, that is not otherwise symbolized. 190 0299 Processing line Some routines in processing software (PROSYS) have limitations on the number of lines, nodes, or areas that can be processed. For example, an area may be associated with no more than 4,751 lines. This code describes a line or lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed. 3.10.4.4 General Purpose Attribute Codes - node, line, or degenerate line 190 0400 Power station or power plant This code describes a power station that is shown by a building symbol appropriate to the size of the structure and labeled as a "power plant" or "power station." If the structure is less than 0.030 inch at its widest dimension and is joined to a power transmission line, it is digitized as a node at the end of the line. If the structure is less than 0.030 inch and separated by a gap from the end of the power transmission line, it is digitized as a degenerate line. If the structure is greater than 0.030 inch in any dimension, the outline of the structure is digitized as a line. 190 0401 Substation This code describes a substation that is shown by symbols 112.56(B), 512.92(C), or 211.13(D). The feature is labeled "substation" or "substa." The feature is digitized as a node if the symbol is less than 0.030 inch and joined to the power transmission line, as a degenerate line if less than 0.030 inch and not joined to the power transmission line, and as a line that defines the perimeter of the substation if the symbol is greater than 0.030 inch in any dimension. The buildings inside the complex are collected in the Manmade Features category. 190 0402 Hydroelectric plant This code is used to describe a hydroelectric plant shown by a building symbol appropriate to the size of the structure and labeled "hydroelectric plant." The feature is digitized according to the same instructions as given for code 190 0400. 190 0403 Landing strip, airport, or perimeter of airport This code is used to describe a landing strip, airport, or the perimeter of an airport. When shown by symbols 116.16(B), 516.26(C), or 2110.08(D) the feature is digitized by a line that follows the runway pattern shown on the map. If the symbol is more than 0.010 inch wide, digitize the outline of the runways. On 1:24,000-scale maps the extent of the airport may be shown by a dashed line around the perimeter, as shown in symbols 209(A) or 2107.06 (D); the runways may be defined by a solid line, as shown by symbol 2110.08(D); or the runways may be shown by a screened area, with a solid line defining the perimeter of the taxiways and aprons, as shown by symbols 511.31(C) or 516.26(C). Digitize lines to define the runways, taxiways, aprons, and the boundary of the airport if available. If it is not possible to distinguish the runway, taxiway, or apron boundaries from adjacent access roads or other features, digitize the airport boundary only. If a landing strip is shown by a single line then digitize the line. Add code 190 0605 if the line is dashed to indicate a loose or turf surface as shown by symbol 511.30(C). If the perimeter of the airport is not clear and the runways are not shown, then place a degenerate line in the approximate center of the airport or landing field and identify it with this code and with code 198 0000. 190 0404 Heliport, perimeter of heliport This code describes a heliport facility. A heliport is shown by symbols 198, 209 (A); 112.4, 116.15 (B); 511.32, 511.33 (C); or 2111.16(D). When shown by symbols 198(A), 112.4(B), or 511.33(C), which are the located object symbols, the feature is digitized as a degenerate line. If shown by symbols 209(A) or 116.15(B), then the feature is digitized as a line that defines the perimeter of the heliport. Symbol 511.32(C) illustrates a solid line around the perimeter of the facility and is digitized as an area. 190 0405 Launch complex, perimeter of launch complex This code describes a feature that is labeled launch complex. There is no standard symbol for this feature. If the limit of the complex is discernible, digitize a line to define the perimeter. If the limit is not clearly defined, digitize a degenerate line in the approximate center of the facility and identify it with this code and with code 198 0000. 190 0406 Pumping station or compressor station This code describes a pumping station or compressor station associated with a gas or oil pipeline. If the feature is shown by a dot on the pipeline, digitize a node and use this code. If the feature is shown separated from the pipeline, digitize it as a degenerate line and describe it with this code. If the feature is shown by symbol 512.67(C), digitize a line by following the perimeter of the area labeled "pumping station" and give it this code. The buildings inside the complex are collected in the Manmade Features category. 190 0407 Seaplane ramp or landing area This code describes a seaplane ramp or landing area that is shown by a variety of treatments on the 1:24,000-scale map and labeled. The feature is digitized by a centerline in a landing strip or a line around the perimeter of a ramp depending on the way the feature is shown. 190 0408 Measuring station, or valve station This code describes a measuring station or valve station associated with a gas or oil pipeline that is shown by a building symbol appropriate to the size of the structure and labeled. This feature is digitized according to the same instructions as given for code 190 0400. 3.10.4.5 Descriptive Attribute Codes 190 0600 Underground This code describes a feature that is labeled "underground." It is not used for a pipeline that is assumed to be an underground feature. 190 0601 Under construction This code describes any feature that is labeled "under construction." 190 0602 Abandoned This code describes any feature that is labeled "abandoned." 190 0603 Above ground This code describes any feature that is labeled "above ground." It is not used on the features that by definition are assumed to be above ground. 190 0604 Closed This code describes any feature that is labeled "closed." 190 0605 Unimproved, loose surface This code describes an aircraft landing strip that is shown by a dashed line to indicate a loose surface. This code does not apply to 1:100,000-scale maps. 190 0606 Submerged This code describes a pipeline that is submerged. 190 0607 Nuclear This code describes a power plant that is labeled "nuclear." 3.10.4.6 Parameter Attribute Codes 190 0000 Photorevised feature This code is described in section 3.3.3. 198 0000 Best estimate of position or classification This code is described in section 3.3.3. 199 00-- Coincident feature This code is described in section 3.3.3. (Current version containing all Changes through 4/7/94) 3.11 MANMADE FEATURES--MAJOR CODE 200 3.11.1 General Principles The purpose in digitizing manmade features is to collect information on the cultural features not included in the other data categories described in this standard. The information is gathered in a manner that permits the extraction and derivation of data to satisfy the needs of the various data users. The symbolization of the features collected in this category varies according to the scale of the map and the size of the feature. The symbols referenced for manmade features are often a guide to the treatment of a structure shown to scale rather than a standard symbol. At the beginning of the instructions for the use of each type of attribute code, general directions for the method of applying attribute codes to different feature treatments are given. Any further instructions or explanations peculiar to a specific attribute code appears with that code. 3.11.1.1 Manmade Features Attribute Codes The attribute codes authorized for use on manmade features are listed in this section. Descriptions of the codes are in sections 3.11.2 through 3.11.8. o Node attribute codes None o Area attribute codes 000 0000 Outside area 200 0100 Church complex (convent, retreat, and so on) 200 0101 School campus (university, college, and so on) 200 0102 Hospital complex (sanatorium, nursing home, and so on) 200 0103 Orphanage 200 0104 Prison compound 200 0105 Trailer park 200 0120 Ski area 200 0122 Athletic field 200 0123 Golf course 200 0124 Shopping center 200 0125 Zoo 200 0126 Drive-in theater 200 0127 Racetrack or raceway 200 0128 Playground 200 0140 Marina 200 0141 Cable area 200 0150 Built-up area 200 0160 Industrial park 200 0161 Materials storage area 200 0162 Refinery or industrial plant 200 0163 Tailings 200 0164 Intricate surface area 200 0165 Oil sump or sludge pit 200 0180 Tank farm 200 0181 Feedlot 200 0182 Experimental farm 200 0183 Proving grounds 200 0184 Firing range 200 0190 Void area o Line attribute codes 200 0200 Conveyor 200 0201 Boardwalk 200 0202 Wall 200 0203 Sea wall 200 0206 Fence line 200 0207 Flume (nonwater) 200 0209 Sewer line 200 0211 Coke ovens 200 0212 Recreational slide 200 0213 Screen (drive-in theatre) 200 0214 Drag strip, racetrack, or raceway 200 0215 Athletic track 200 0250 Arbitrary closure line 200 0299 Processing line o Single-point attribute codes (degenerate line) 200 0300 Grave site 200 0301 Historical marker 200 0302 Mine tunnel entrance or cave 200 0303 Mine shaft 200 0304 Prospect 200 0305 Tower 200 0306 Burner/stack 200 0307 Drilled well 200 0308 Cliff dwelling 200 0309 Light 200 0310 Brick kiln 200 0311 Drill hole 200 0314 Guzzler 200 0315 Located object or landmark object 200 0316 Campsite 200 0317 Wind generator o General purpose attribute codes (apply to nodes, areas, lines, or degenerate lines). 200 0400 Building 200 0402 Church 200 0403 School 200 0404 Municipal building 200 0405 Courthouse 200 0406 Post office 200 0407 City or townhall 200 0408 Hospital 200 0409 Prison 200 0410 Town, village, settlement, locality, or unincorporated village 200 0411 Amphitheater 200 0412 Customs building 200 0420 Cemetery 200 0421 Sewage disposal plant 200 0422 Waterworks 200 0423 Oil reservoir 200 0424 Drilled well field 200 0425 Tank 200 0426 Offshore oil or gas platform 200 0427 Mine dump 200 0428 Open pit mine 200 0429 Quarry 200 0430 Strip mine 200 0431 Landfill 200 0432 Pit, unconsolidated material 200 0433 Radio or television facility 200 0434 Storage bin 200 0435 Levee 200 0436 Spoil bank 200 0438 Reclaimed area 200 0445 Fairgrounds 200 0446 Rodeo grounds 200 0447 Corral 200 0448 Boat ramp 200 0449 Campground 200 0450 Fort 200 0451 Swimming pool 200 0452 Archeological site, ruin, or Indian mound 200 0453 Recreation area, public use area 200 0454 Picnic area 200 0455 Port of entry 200 0456 Stadium 200 0465 Pile, dolphin, stump, or snag 200 0466 Breakwater, jetty, pier, dock, causeway, or wharf 200 0467 Exposed wreck or wreckage 200 0468 Sunken wreck 200 0469 Drydock o Descriptive attribute codes 200 0601 Underground 200 0602 Under construction 200 0603 Abandoned 200 0604 Water 200 0605 Oil 200 0606 Gas 200 0607 Chemical 200 0608 Covered 200 0609 Gravel 200 0610 Sand 200 0611 Clay 200 0612 Borrow 200 0613 Radio 200 0614 Lookout 200 0615 Unincorporated 200 0616 No population 200 0617 Submerged 200 0618 Ruin 200 0619 Caliche 200 0620 Chert 200 0621 Cinder 200 0622 Pumice 200 0623 Shale 200 0624 Scoria o Parameter attribute codes 200 0000 Photorevised features 202 ---- Width in mils of feature to scale 208 0000 Best estimate of position or classification 209 00-- Coincident feature or symbol 3.11.2 Node Attribute Codes There are no attribute codes for nodes in this category. 3.11.3 Area Attribute Codes Area attribute codes identify an area point digitized within a feature that is greater than 0.030 inch in length or width as depicted on the map. Area attribute codes do not identify either the line that outlines the area or the individual features that appear within the area, such as buildings within a hospital complex. Individual buildings within the area are also digitized as appropriate to their size and class (see section 3.11.6). The determination of the extent of an area is simple when the outline is a special symbol, such as symbol 209(A), which outlines a cemetery as shown in symbols 214 or 215 (A). The outline may also be a symbol in another category, such as a road that delimits a trailer park. The determination of the extent of the area is more difficult if the outline is formed by the omission of urban or woodland tint, as is done for a school complex, or formed by the juxtaposition of cleared areas and other features, as is done for tank farms or ski areas. In such cases, the placement of the outline must be based on judgment. The rules for coding the line that delimits an area are in section 3.11.4. 000 0000 Outside area This code is described in section 3.3.3. 200 0100 Church complex (convent, retreat, and so on) This code identifies an area that has a name or label indicating that it is a church complex. The area contains buildings shown by symbols 168-170, 172-173 (A); 112.1(B); or 2106.05(D) (see code 200 0402). 200 0101 School campus (university, college, and so on) This code identifies an area that has a name or label indicating that it is a school campus. The area contains buildings shown by symbols 166, 167, 170-173 (A); 112.1(B); or 2106.04(D) (see code 200 0403). 200 0102 Hospital complex (sanitarium, nursing home, and so on) This code identifies an area that has a name or label indicating that it is a health care complex. The area contains individual buildings (see code 200 0408). 200 0103 Orphanage This code identifies a large building or complex that has a name or label indicating that it is an orphanage or institution housing children. If shown as a complex, the area contains individual buildings (see code 200 0400). 200 0104 Prison compound This code identifies an area that has a name or label indicating that it is a prison or detention center. If the area is without a defined boundary, represented by a group of buildings, then digitize the area and assign this code. If the area is clearly defined by military reservation boundary symbols 207(A), 112.78(B), 512.28(C), or 2107.05(D), the boundary is collected in the Boundaries category. When the area contains individual buildings, see codes 200 0409 and 200 0400. 200 0105 Trailer park This code identifies an area labeled as a trailer park. The outline of the trailer park may be formed by a road pattern. If so, do not encode the outline as being coincident with a transportation feature. This is because the digitized outline of the trailer park follows the road casing, whereas the road itself has a centerline digitized, so the two lines are not coincident. 200 0120 Ski area This code identifies an area determined to be a ski area by the presence of ski lifts and slopes. The ski lifts are digitized in the transportation category. The area contains individual buildings (see code 200 0400). 200 0122 Athletic field This code identifies an area that contains one or several athletic fields that is defined by symbols 209(A) or 2107.06(D). These may include and be labeled as running tracks, soccer fields, football fields, baseball diamonds, and so on, which are associated with a recreational area or school system. When the athletic field is adjacent to a school it is shown by symbol 516.16(C) and is not labeled. Digitize an area enclosing the track and give it this code. See code 200 0215 for coding the tracks. 200 0123 Golf course This code identifies an area, shown by symbol 2111.17(D), that is labeled as a golf course or country club regardless of size. The outline of this area is determined according to its relationship to delimiting features, such as rivers, railroads, or house omission tint and so on. Disregard woodland tint that separates the fairways. The area may contain individual buildings (see code 200 0400). If it is not possible to distinguish the outline, then digitize a degenerate line on the first letter of the golf course label. 200 0124 Shopping center This code identifies an area in which a building or group of buildings is labeled as a shopping center. The area does not include the parking areas adjacent to the buildings, if shown, that are collected with the Roads and Trails overlay. 200 0125 Zoo This code identifies an area that is labeled as a zoo, zoological park, or wild animal park. 200 0126 Drive-in theater This code identifies an area defined by symbols 252(A), 512.68(C), or 2111.08(D). The interior structures are digitized and coded (see codes 200 0400 and 200 0213). 200 0127 Racetrack or raceway This code identifies an area labeled as a site of horse races or motorized vehicle races and labeled "race track" or "raceway." The area includes operator areas, stands, infields, pit areas, and so on. It does not include adjacent parking areas. This area may include interior structures such as racetracks and grandstands shown by symbols 116.9(B), 516.15(C), or 2110.10(D). Significant interior structures are digitized and coded (see codes 200 0400 and 200 0214). 200 0128 Playground This code identifies an area labeled "playground." 200 0140 Marina This code identifies an area labeled "marina." This area is located along the shore of a navigable waterway and may contain a concentration of dock or pier structures (code 200 0466), boathouses, and other related buildings (see code 200 0400). 200 0141 Cable area This code identifies an area delineated by symbols 245(A), 512.143(C), or 2113.06(D) and labeled as the site of underwater cable placement. The area normally is open ended and requires closing by the use of two arbitrary closure lines (see code 200 0250). 200 0150 Built-up area This code has traditionally been applied to areas delineated by symbols 520(A), 115.1(B), 515.1(C), or 2110.11(D), but the minimum allowable size, density criteria, and exclusions for built-up area have been revised. As a result, there may be areas on the graphic that did not meet the previous criteria for built-up area, but do meet the revised criteria. These areas will be collected as built-up area. Built-up area is defined as an area of intensive use, with much of the land covered by structures. The limits of the built-up area are determined by the relative concentration of buildings and associated intensive use areas, such as parking lots, and the existence of a systematic street pattern. Density of building and associated use areas will vary from densely concentrated areas downtown, to moderately concentrated residential areas where most of the property is developed. Built-up area is collected if the area is at least 30% built-up and is at least 40 acres in size, and has a minimum width of 660 feet. Built-up area does not refer to political boundaries and may include incorporated and unincorporated areas as well as military reservations. Although built-up area limits need not be fixed in relation to linear features, where practical, the limits of built-up area should share the edge with other linear features such as streams, boundaries, roads, railroads, etc. The outline of built-up area should be relatively smooth. It should not be extended to include a few buildings nor to exclude a few buildings when the smoothness of the edge would be effected. When the perimeter streets are at least 30% developed, the built-up area should be extended across the street to include these buildings. Housing developments where the street network is complete and building development is well underway, and it can be anticipated that most of the development will be occupied, should be collected as built-up area. Narrow strips where there is only a road and buildings along both sides of the road should not be collected as built-up area, even if they would connect an adjoining larger built- up areas. A large built-up area that is separated from a smaller isolated built-up area may be extended to include the smaller area, if the smaller area is within 660 feet of the larger built-up area. Within a built-up area, areas which are less than 30% developed, and are at least 80 acres in size, with a minimum width of 660 feet, are not collected as built-up. In addition, if canal/ditches, lake/ponds, reservoirs, stream/rivers, swamp/marshes, parks, railway yards, runways, air facilities, cemeteries, golf courses, or exhibition grounds (fairgrounds) are collected as areas within a built-up area they are not also collected as built-up. All other area features collected within a built-up area are also collected as built-up areas. See section 3.11.6 for information on which buildings are collected within built-up areas. 200 0160 Industrial park See code 200 0162. 200 0161 Materials storage area See code 200 0162. 200 0162 Refinery or industrial plant This code and codes 200 0160 and 200 0161 identify areas labeled to indicate a particular industrial feature. On 1:24,000-scale source, the area may contain buildings (see code 200 0400). Do not use these codes for tank farms or oil and gas fields. 200 0163 Tailings This code identifies an area of tailings shown by symbols 324(A), 135.3(B), 535.4(C), or 2112.05(D) and labeled. Tailings are the discarded material from ore processing or dredge operations piled in irregular heaps and labeled "tailings" or "dredge tailings." 200 0164 Intricate surface area This code describes an area shown by symbol 328(A). This type of area may be labeled as a disturbed surface. Do not use this code if the area is labeled "strip mine" (see code 200 0430) or "Lava" (see code 080 0104). This feature may be added through photorevision and shown in purple (see code 200 0000). 200 0165 Oil sump or sludge pit This code identifies an area shown by symbols 250(A), 512.86(C), or 2111.07(D) and labeled. 200 0180 Tank farm This code identifies an area labeled "tank farm" that encompasses a group of tanks. The tanks in the interior of the area are digitized (see code 200 0425). The tank farm outline, if not clearly demarcated, is obtained by digitizing a line around the outermost tanks. 200 0181 Feedlot This code identifies an enclosed area labeled "feedlot," shown by symbol 2111.14(D). The area may contain individual buildings (see code 200 0400). 200 0182 Experimental farm This code identifies an area labeled to indicate that it is an experimental farm or agricultural research facility. If the area contains individual buildings, see code 200 0400. 200 0183 Proving grounds This code identifies an area labeled or named to indicate that it is a proving ground or testing area. The area may contain individual buildings (see code 200 0400). The outline of the area may be coincident with a military reservation boundary (209 0009). 200 0184 Firing range This code identifies an area labeled or named to indicate that it is a firing range, artillery range, or detonation area. The area may contain individual buildings (see code 200 0400). The outline of the area may be coincident with a military reservation boundary (209 0009). 200 0190 Void area This code identifies an area on the source material where no manmade feature data exist because of replacement by imagery or a pattern from another category. A void area is also found beyond the national boundary to distinguish it from the background area. Where appropriate, the perimeter of the void area, usually a closure line, is coded as coincident with the category that defines the manmade feature void area. The closure line that defines the void area beyond the national boundary is coded as coincident with the Boundaries category (209 0009). 3.11.4 Line Attribute Codes Each line attribute code identifies a line segment digitized along a linear feature. The feature may be digitized in segments as it intersects other features or changes in some way, such as a portion of a levee coincident with a boundary. If the linear feature is represented by a dashed line, the digitized line does not replicate the dashes but is a solid line. For this overlay the line that forms the outline of an area has no assigned attribute code unless: o it is coincident with a linear feature in another category such as a boundary; o the outline is so difficult to determine that it warrants the use of parameter code 208 0000 to indicate the uncertainty of position; o it has been arbitrarily placed to close off a labeled or named area that is not otherwise symbolized, or to complete the closure of a feature partially outlined by a line existing on the source (code 200 0250); or o it is a linear feature in itself, distinct from the area it outlines. 200 0200 Conveyor This code identifies a line labeled "conveyor" or "conveyor belt" and represented by a dashed line on the 1:24,000-scale maps. The dash length and lineweight varies among map sheets. The label might have been omitted on a photorevised conveyor, in which case the conveyor may still be identifiable if it connects a mine or strip mine to a type of plant. 200 0201 Boardwalk This code identifies a centerline digitized in a boardwalk shown by symbols 254(A), 512.71(C), or 2111.09(D) and labeled "boardwalk." If shown to scale (greater than 0.020 inch), also use code 202 0--- to encode the width. 200 0202 Wall This code identifies a line that represents a wall as shown by symbols 192, 193 (A); 512.63, 512.64 (C); or 2110.06, 2110.06 (D) and labeled. If the wall is shown to scale (0.017 inch or greater), digitize a centerline and also use code 202 0--- to encode the width. This code is also used for miscellaneous wall structures, such as stabilizing walls, that are depicted on the graphic source but unlabeled. 200 0203 Sea wall This code identifies a line shown by symbols 159(A), 112.69(B), 512.48(C), or 2108.07(D) and labeled. A sea wall is usually coincident with the shoreline (see code 209 0005). 200 0206 Fence line This code identifies a line shown by symbols 522(A), 523.15(C), or 2110.07(D). 200 0207 Flume (nonwater) This code identifies a line shown by symbol 191(A) or 2110.04(D) and labeled. An appropriate descriptive code is also used to describe the substance being carried by the flume, for example, 200 0605 for oil flume. Water flumes are digitized as part of the hydrography data category. 200 0209 Sewer line This code identifies a line shown by symbols 116.13(B) or 516.24(C). Because the feature is submerged, also use code 200 0617. 200 0211 Coke ovens This code identifies a centerline digitized along symbols 253(A) or 512.70(C). 200 0212 Recreational slide This code identifies a line shown by symbols 188(A), 112.59(B), 512.117(C), or 2110.09(D). A recreational slide is shown on newer maps when it is a permanent installation. 200 0213 Screen (drive-in theater) This code identifies the line within the drive-in theater, shown by symbols 252(A), 512.68(C), or 2111.08(D) that represents the screen. 200 0214 Drag strip, racetrack, or raceway This code identifies a racetrack or raceway shown by symbols 116.9(B), 516.15(C), or 2110.08(D) and labeled. See code 200 0127 to code the surrounding area. This code also identifies a drag strip that is usually shown by a straight segment of road and labeled. 200 0215 Athletic track This code identifies a feature shown by symbol 516.16(C) that is used for track and field athletic events. The track is not named or labeled when it is shown adjacent to a school or other facility. See code 200 0122 to code the surrounding area. 200 0250 Arbitrary closure line This code identifies a line digitized to close off an area that is partially outlined by a line existing on the source. For example, a drive-in theater may have a portion of the normal symbol outline overprinted by another feature. This code is used on the line digitized to close off the open end. This code also identifies a line digitized to close off a labeled or named area that is not otherwise symbolized on the existing source, e.g., town, village, and so on. This code is used on the line digitized to delimit the area. Also use the primary code when appropriate. 200 0299 Processing line Some routines in the processing system (PROSYS) have limitations on the number of lines, nodes, and areas that can be processed. For example, an area may be associated with no more than 4,751 lines. This code describes a line or lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed. 3.11.5 Single-Point Attribute Codes (degenerate lines) A single-point attribute code identifies a degenerate line digitized on a standard USGS symbol. The features identified by these codes are of a size that are represented by a point symbol rather than shown to scale. Unless otherwise specified, the degenerate line is placed in the center of the symbol being digitized. 200 0300 Grave site This code identifies the location of one or two graves shown by a cross and labeled "grave" as in symbols 213(A), 512.119(C), or 2107.07(D). The degenerate line is digitized at the intersection of the cross. It differs from cemetery symbolization by having no boundary. See code 200 0420 for larger cemeteries. 200 0301 Historical marker This code identifies a feature shown by symbols 198(A) or 2111.03(D) (located object) or 112.4(B) (landmark object) and named or labeled. These symbols are used for other landmark features so the label is the distinguishing feature. 200 0302 Mine tunnel entrance or cave This code identifies a feature shown by symbols 184(A), 112.35(B), 512.80(C), or 2109.03(D). The degenerate line is digitized at the intersection of the arms of the symbol. 200 0303 Mine shaft This code identifies a feature shown by symbols 186(A), 112.36(B), 512.81(C), or 2109.05(D). 200 0304 Prospect The code identifies a prospect shown by symbols 185(A), 512.82(C), or 2109.04(D). A prospect is an excavation for the purpose of mineral exploration that is smaller than a mine tunnel or shaft. A degenerate line is digitized on the intersection of the arms of the symbol. 200 0305 Tower This code identifies a feature shown by symbols 198(A), 112.4(B), or 2111.03(D). These symbols are used for other landmark features, so the label is the distinguishing feature. If the label specifies the type of tower (radio or lookout) also use the appropriate descriptive code (200 0613 or 200 0614). 200 0306 Burner/stack This code identifies a feature shown by symbols 198(A) or 2111.03(D), which is labeled as a burner or stack. The symbol is used for other landmark features so the label is the distinguishing feature. 200 0307 Drilled well This code identifies a feature shown by symbols 194(A), 112.101(B), 512.83(C), or 2111.01(D) and labeled as an oil or gas well. Also use codes 200 0605 (oil) or 200 0606 (gas) to specify the type of well. Only offshore wells are symbolized on 1:100,000-scale sources and are shown as platforms (see code 200 0426). This code does not apply to water wells, which are digitized in the hydrography category. 200 0308 Cliff dwelling This code identifies a feature shown by symbols 182(A), 112.34(B), 512.79(C), or 2106.10(D) and named or labeled. 200 0309 Light This code identifies a feature shown by symbols 198(A), 112.102(B), 512.163(C), or 2111.15(D) and labeled "Light." 200 0310 Brick kiln This code identifies a feature shown by a circle 0.030 inches in diameter that is labeled "brick kiln." 200 0311 Drill hole This code identifies a feature shown by symbols 198(A), 112.101(B), or 2111.03(D) and labeled "drill hole." 200 0314 Guzzler This code identifies a feature shown by symbols 198(A), or 2111.03(D) and labeled "guzzler." 200 0315 Located object or landmark object This code identifies a feature shown by symbols 198(A), 112.4(B), 512.72(C), or 2111.03(D) and NOT labeled. 200 0316 Campsite This code identifies a feature shown by symbol 512.72(C) and labeled. 200 0317 Wind generator This code identifies a feature shown by the windmill symbol 199(A), 112.3(B), 512.69(C), or 2111.04(D), and labeled "wind generator." 3.11.6 General Purpose Attribute Codes A building shown by a minimum size symbol, or a building less than 100 feet along the longest axis, is collected as a single-point feature (degenerate line). A building that is 100 feet or more along the longest axis is collected as an area. The outline of the area is treated in accordance with the directions given in the introduction of section 3.11.3. Within a built-up area (200 0150), collect only buildings that are at least 400,000 square feet, or can be described as an arena, auditorium, armory, capitol, city hall (200 0406), community center, courthouse (200 0405), firehouse (200 0404), hospital (200 0408), house of worship (200 0402), library, medical center (200 0408), memorial, museum, post office (200 0406), railroad station, school (200 0403), stadium, or town hall (200 0407). Note that specific codes do not exist for all of these building types; in these cases the building code (200 0400) is used. Also note that railroad station is collected in the Pipelines, Transmission Lines, and Miscellaneous Transportation Features category. Outside built-up area, collect all buildings according to codes that follow. A building that is shown with a purple photorevised addition is digitized as two separate buildings. The original portion of the structure is identified with the appropriate codes. The purple portion is identified by the same codes and is, in addition, assigned code 200 0000 (photorevised feature). 200 0400 Building This code is used for all buildings that were previously attributed as class 1 or class 2. All buildings shown by symbols 163, 164, 165 (A); 112.1(B); 512.52, 512.53 (C); or 2106.01 through 2106.03 (D); and buildings shown by old symbols 175, 176 (A) or 512.57, 512.58 (C) are given this attribute code. This code is not used on buildings that have a specific code, such as church or hospital. It is used, however, on buildings that in themselves have no other specific code but are located within a coded area. One example is a building within a prison compound (see code 200 0409). 200 0402 Church This code identifies a building shown by symbols 168-170, 172 (A), 512.55(C), or 2106.05(D). This code is also used on buildings shown by these symbols that are located within an area coded as a church complex (see code 200 0100). 200 0403 School This code identifies a building shown by symbols 166-167, 170-173 (A); 512.54, 512.56 (C); or 2106.04(D). This code is also used on buildings shown by these symbols that are located within an area coded as a school complex (see code 200 0101). 200 0404 Municipal building This code identifies a government building shown within an urban area by the building symbol, other than a courthouse, post office, city, or townhall. Examples of municipal buildings are fire stations, police stations, or city animal pounds. 200 0405 Courthouse This code identifies a building labeled as a courthouse, regardless of jurisdiction. 200 0406 Post office This code identifies a building labeled as a post office. 200 0407 City or townhall This code identifies a building labeled as a city or townhall. 200 0408 Hospital This code identifies a building labeled as a hospital. The code is used on all buildings within an area coded as a hospital complex (200 0102). 200 0409 Prison This code identifies a building labeled as a prison. The code is used on the largest buildings within an area labeled as a prison compound. All other buildings are coded 200 0400. 200 0410 Town, village, settlement, locality, or unincorporated village This code identifies a location designated, by a label or name, as a site of habitation by groups of humans. The localities that have a definite symbolized boundary are represented in the Boundaries category. This code is intended to identify unincorporated villages that on the 1:24,000-scale sources have no boundaries shown, as well as towns, villages, and settlements that on the 1:100,000-scale sources are represented by a dot, street pattern, or road intersection. When groups of buildings or street patterns represent the locality, digitize a line depicting the limits of the area, which includes the name or label and related buildings and streets (see code 200 0250). When the symbol 112.42(B) represents the locality, digitize a degenerate line on the dot and identify it with this code. If the locality is shown by a road intersection, digitize a degenerate line at the intersection and identify it with this code. If a locality is named for a point feature appearing on the map, and there are no other features, e.g., buildings, digitize a degenerate line on the symbol. However, if the symbol does not appear on the map, then digitize a degenerate line near the name. In addition, if the locality is labeled as unincorporated, also use code 200 0615; if unpopulated, use code 200 0616. 200 0411 Amphitheater This code identifies a structure generally symbolized by a 0.003-inch solid outline that is compiled to scale and labeled. 200 0412 Customs building This code identifies a building shown by symbols 163, 165 (A); 112.1(B); 512.52, 512.53 (C); or 2106.01 through 2106.03 (D) and labeled. 200 0420 Cemetery This code describes a burial site of more than two graves with a delineated boundary that is shown by symbols 213, 214, 215 (A); 112.72, 112.73 (B); 512.120, 512.121 (C); or 2107.07, 2107.08 (D). If the symbol is 0.030 inch or less on the longest side, digitize a degenerate line on the symbol and identify it with this code. If the symbol size is greater than 0.030 inch on the longest side, then digitize the cemetery as an area. Because the outline of national cemeteries is shown by boundary symbols 202(A), 112.74(B), 512.123(C), or 2107.01 (D), also assign the coincident feature code 209 0009 to the outline of a national cemetery. 200 0421 Sewage disposal plant This code identifies the prominent building associated with a labeled sewage disposal facility. The sewage disposal ponds and filtration beds are digitized in the Hydrography category. 200 0422 Waterworks This code identifies the prominent building associated with a labeled waterworks or water treatment plant. Any reservoirs or ponds are digitized in the Hydrography category. 200 0423 Oil reservoir This code identifies a feature shown by symbols 251(A) or 512.87(C). If the symbol diameter is 0.030 inch or less, digitize a degenerate line in the center of the symbol. If the diameter is greater than 0.030 inch, digitize the feature as an area. 200 0424 Drilled well field This code identifies an area of drilled oil or gas wells. It is labeled "oil field" or "gas field," or "oil and gas field." On 1:24,000-scale maps it contains numerous wells as shown by symbols 194(A), 512.83(C), or 2111.01(D). On 1:100,000-scale maps the name or label is shown in the location. When it is possible to determine the extent of the oil or gas field, digitize it as an area. If the extent cannot be determined, or if the source is a 1:100,000-scale map that only has a label, then digitize a degenerate line on the first letter of the label. Also use the appropriate descriptive code to specify oil or gas or both (see codes 200 0605 and 200 0606). 200 0425 Tank This code describes tanks shown by symbols 196(A), 112.2(B), 512.65(C), or 2111.02(D); or shown by old symbols 197(A) or 512.66(C). Any tank 0.030 inch or less in diameter is digitized as a degenerate line. Any tank greater than 0.030 inch in diameter is digitized as an area. Also use the appropriate descriptive code to specify the contents (see codes 200 0604 through 200 0607). 200 0426 Oil or gas platform This code describes an offshore oil or gas platform shown by symbols 116.11(B) or 516.22(C). It is labeled "oil platform," "gas platform," or "oil and gas platform." If the square is 0.030 inches or less, digitize a degenerate line on the symbol. If the symbol is greater than 0.030 inches, digitize it as an area. Also use the appropriate descriptive code to specify oil or gas, or both (see codes 200 0605 and 200 0606). 200 0427 Mine dump This code identifies a mine dump, which is a pile of waste rock, from a mine. It is shown by a variety of treatments all of which are labeled "mine dump." When the mine dump is shown by symbols 327(A) or 532.23(C) digitize a centerline in the symbol from one end to the other, at right angles to the tick marks. When the mine dump is large and has a regular hill-like shape, it may be shown by contours only, and is digitized as an area. Outline the area, but do not digitize the contours. This applies to 1:24,000-scale maps. A large mine dump of an irregular shape covering a large area that may not be evident from the contours is overprinted with the intricate surface pattern as shown by symbols 328(A) or 535.4(C). Digitize an area outlined by the edge of the pattern. This applies to 1:24,000-scale maps. On Provisional Edition Maps all mine dumps are shown by symbol 2112.05(D) and labeled. On 1:100,000-scale maps all mine dumps are shown by symbol 135.3(B). This symbol is digitized as an area and is distinguished from other disturbed surfaces only by the label. 200 0428 Open pit mine This code describes an open pit mine, which may be shown by a variety of treatments all of which are labeled "open pit mine." When the open pit mine is shown only by the crossed-pick symbols 183(A), 112.37(B), 512.84(C), or 2109.01(D) (without tint), digitize a degenerate line at the intersection of the symbol. When an open pit mine is shown by symbols 333(A), 535.3(C), or 2112.08(D) digitize as an area. The outline of the area is formed by digitizing a centerline through the brown hachures of symbol 333(A) or along the edge of the brown tint of symbol 512.84(C). This applies to 1:24,000-scale maps. On 1:24,000-scale maps, there are large open pit mines that are shown entirely by contouring and a label. These may have structures, water bodies, roads, and railroads inside the pit. This feature treatment is digitized as an area. The outline of the area is the outermost contour line of the pit. On Provisional Edition Maps all open pit mines are shown by symbol 2112.08(D) and labeled. On 1:100,000-scale maps, large open pit mines are shown by symbol 135.2(B) and labeled. This symbol is digitized as an area by following the edge of the pattern. 200 0429 Quarry A quarry is an open pit from which rock or stone is excavated. It is shown by the same symbology as the open pit mine but is labeled "quarry." The feature is digitized in the same manner as described in the instructions for code 200 0428. 200 0430 Strip mine A strip mine is a shallow surface excavation that may be digitized in one of two ways, which depends on the symbolization shown on the source. When a linear strip mine is shown by a narrow strip of disturbed surface, 0.030 inch or less in width, between two contour lines as shown in symbols 326(A), 535.2(C), or 2112.06(D) digitize centerline of the pattern. If the strip of disturbed surface is greater than 0.030 inch, digitize it as an area. Digitize the contour line as the outline of the strip mine. When the strip mine is shown by symbols 325(A), 135.1(B), 535.1(C), or 2112.06(D) digitize an area. The outline of the area is the edge of the disturbed surface pattern or tint. 200 0431 Landfill This code describes a feature shown by the symbol 328(A) that is labeled "landfill." If the area of the landfill is 0.030 inch or less in diameter, digitize it as a degenerate line. If the area is greater than 0.030 inches in diameter, digitize the area. The outline of the area is the edge of the disturbed surface pattern. 200 0432 Pit, unconsolidated material A pit is an excavation of unconsolidated materials such as sand, gravel, or clay. It is also called a borrow pit when earth was removed for construction purposes. It is shown by symbols 333(A), 112.38, 135.4 (B), 535.5(C), or 2112.08(D) with a crossed shovel instead of a crossed pick. When the pit is shown by symbols 255(A), 112.38(B), 512.85(C), or 2109.02(D) without the brown tint, then digitize a degenerate line at the intersection of the crossed shovels. When the pit is shown by symbols 333(A), 112.38(B), 512.85(C), or 2112.08(D) with tint, digitize it as an area. Digitize a centerline through the brown hachures of symbol 333(A) or a line along the edge of the brown tint pattern of symbols 112.38(B) or 512.85(C). For all cases, also use the appropriate descriptive code to describe the specific type of pit. 200 0433 Radio or television facility This code identifies a feature labeled as a radio facility. The facility may be one or more buildings. Digitize the buildings according to the instructions for code 200 0400 and identify each with this code. Do not use this code for a radio tower (see code 200 0305). 200 0434 Storage bin Storage bins may be symbolized as tanks or as buildings, but with the label "storage bin" or "silo." Digitize the storage bin according to the instructions for code 200 0425 or 200 0400, as appropriate, and identify with this code. 200 0435 Levee, dike This code identifies a line shown by symbols 314 through 315(A); 132.13(B); 532.9, 532.11, 532.12 (C); or 2112.01, 2112.02 (D) or an area shown by contours that may or may not be labeled. When the linear symbols are used, digitize a line and identify it with this code. When shown by contours, digitize an area and identify it with this code. The perimeter of an areal feature are digitized as an arbitrary closure line (200 0250) because the limit is not explicitly symbolized. When the levee is shown by symbols 315(A), 532.12(C) or 2112.02(D), the centerline is digitized along the road or railroad and is also coded with feature codes 209 0017 or 209 0018 to indicate coincidence. On the 1:100,000-scale sources a levee carrying a road or railroad is not shown; instead the road or railroad is labeled "road on levee" or "railroad on levee." For these cases digitize the centerline of the road or the railroad and also use the coincident feature codes 209 0017 or 209 0018. 200 0436 Spoil bank This code identifies a feature generally shown by symbols 332(A), 532.13(C), or 2112.01(D). A spoil bank is a linear accumulation of dredged material commonly associated with a ditch or dredge tailings. The digitized line is not broken where the spaces in the symbol occur. A large spoil bank may be shown by contours and labeled. This is digitized as an area. 200 0438 Reclaimed area This code describes an area, bounded by dashed purple lines, which contains contours overprinted with symbol 328(A) and labeled "reclaimed area." If the area is not labeled, a note is added to the legend of the map that identifies the area as "reclaimed mining." This code also identifies an area represented by a 4% purple tint and labeled "reclaimed strip mine." Digitize an unattributed solid line by following the dashed outline or edge of the pattern and assign this code to the area. 200 0445 Fairgrounds This code describes a feature that is labeled as fairgrounds or parade grounds, whether State, county, or local. The fairgrounds is digitized as an area if the outline can be determined. If it is not possible to distinguish the outline, then digitize a degenerate line on the first letter of the fairgrounds label. 200 0446 Rodeo grounds This code describes a feature that is labeled as rodeo grounds. It is digitized as an area if the outline can be determined. If it is not possible to distinguish the outline, then digitize a degenerate line on the first letter of the rodeo grounds label. 200 0447 Corral A corral is a fenced animal enclosure shown by symbols 258(A) or 112.44(B). When shown by symbol 258, digitize the feature as an area. When shown by symbol 112.44, digitize the feature as a degenerate line. 200 0448 Boat ramp A boat ramp is shown to scale in all cases. It may be any shape and size and, therefore, is digitized according to the following general instructions. A boat ramp shown by a symbol of 0.030 inch or less on the longest side is digitized as a degenerate line. A boat ramp shown by a single line as in symbol 516.14(C) is digitized as a line. A boat ramp shown by a symbol greater than 0.030 inch on the longest side is digitized as an area. 200 0449 Campground This code identifies a feature shown by symbols 257(A), 112.48(B), 512.115, or 2111.11(D) and labeled. If the outline of a campground can be determined, digitize it as an area. If the outline cannot be determined, digitize a degenerate line in the center of the base of the tepee symbol. 200 0450 Fort A fort is a building or complex named or labeled to indicate that it is a fort. If the fort is without a defined boundary, represented by a group of buildings, and the outline can be inferred, it is digitized as an area and assigned this code. If the fort is a clearly defined complex, with a military reservation boundary shown by symbols 207(A), 112.78(B), 512.128(C), or 2107.06(D) defining the area, the area and boundary are collected in the Boundaries category. Digitize any interior structures as appropriate for their class. If the fort is shown as an individual building, follow the general instructions for the digitizing of structures and give the feature this code. Historic forts may be shown by the located object symbols, 198(A), 112.4(B), or 2111.03(D). In this case, digitize a degenerate line on the symbol. 200 0451 Swimming pool This code identifies a feature shown by symbols 179(A), 512.60, 545.4 (C), or 2205.01(D); labeled "swimming pool" on earlier map editions. On later editions, this symbol is not labeled but bears a resemblance to a reservoir. If the symbol is 0.030 inch or less on the longest side, digitize a degenerate line on the center of the symbol. If the symbol is greater than 0.030 inch on the longest side, digitize it as an area. If this symbol is not labeled, also use code 208 0000 (best estimate). 200 0452 Archeological site, ruin, or Indian mound This code describes a structure of historical significance, protected by Federal or State agencies, shown by symbols 181(A), 112.33(B), 512.78(C), or 2106.09(D). If the symbol is 0.030 inch or less on a side, digitize a degenerate line in the center of the symbol. If the symbol is greater than 0.030 inch on a side, digitize it as an area. Note that the outline of the symbol is solid rather than dashed if the symbol is less than 0.050 by 0.050 inch in size (both in reference A and reference B). This code also describes an Indian mound that is shown by contours and a name or label. An unattributed line is digitized to define the perimeter of the area, by following the contour shown as the base of the mound. If the area defined is 0.030 inch or less in diameter, digitize a degenerate line inside the contour shown as the top of the mound. 200 0453 Recreation area, public use area This code identifies a feature labeled as a recreation or public use area, other than National or State areas that are identified in the Boundaries category (section 3.8). This includes roadside parks and viewpoints, vantage points, and overlooks. If the outline of the recreation area can be determined, digitize it as an area. Digitize any structures within the area as appropriate. If the outline of the area cannot be determined, digitize a degenerate line on the first letter of the name or label that identifies the recreation area. 200 0454 Picnic area This code identifies a feature shown by symbols 256(A), 112.47(B), 512.116(C), or 2111.10(D). If the outline of the picnic area can be determined, digitize the feature as an area. If the outline cannot be determined, digitize a degenerate line on the center of the picnic table symbols. 200 0455 Port of entry A port of entry is a building located at a point of entry on the national boundary, shown by symbol 112.43(B). Digitize the structure according to the instructions for buildings (see code 200 0400). 200 0456 Stadium This code identifies a sports stadium that is not associated with a school. The classification does not include parking lots or other structures adjacent to the stadium. Digitize stadiums shown by symbol 112.8(B) to scale and apply this code to the area. No symbol is shown for a stadium in reference A, rather the structure is shown as a building and labeled. In such cases digitize the building as an area and give it this code. 200 0465 Pile, dolphin, stump, or snag This code identifies a feature shown by symbol 235(A). When the feature is shown by the single circle, digitize a degenerate line in the circle. When the feature is shown by the circle of dots, digitize it as an area. Digitize a line on the circle of dots to form an outline. The feature may also be shown by a dashed line and labeled "Pilings," in which case it is digitized as a line. 200 0466 Breakwater, jetty, pier, dock, causeway, or wharf This code identifies features shown by symbols 156-158 (A); 112.69, 112.70, 112.96 (B); 512.43 through 512.45, 512.162 (C); or 2108.05, 2108.06 (D). When the feature is shown by a line as in symbols 156(A), 112.69(B), or 512.43(C), it is digitized as a line. When shown by symbols 112.70(B), or 512.46, 512.47 (C) also use this code to indicate that it is a ruined structure (see code 200 0618). When shown by symbols 157(A) or 512.44(C), digitize it as an area. Use an arbitrary closure line (see code 200 0250) to close the landward end of the symbol. When shown by symbols 158(A) or 512.45(C), also use this code to indicate that the feature is covered (see code 200 0608). When shown by symbol 512.162(C), also use this code to indicate that the feature is submerged (see code 200 0617). 200 0467 Exposed wreck or wreckage This code identifies a feature shown by symbols 239, 240 (A); 512.139, 512.140 (C); or 2113.05(D). When shown by symbol 239 digitize a degenerate line on the center of the ship. When shown by symbol 240, digitize the feature as an area. Digitize the line of dots as the outline of the area. 200 0468 Sunken wreck This code identifies a feature shown by symbols 241, 242 (A), or 512.141(C). When shown by symbol 242(A), digitize the feature by placing a degenerate line on the center of the symbol. When the masts are exposed on a sunken wreck as shown by symbols 241(A) or 512.141(C), digitize the feature as an area. Place the area point on the center of the symbol. Digitize a line on the circle of dots for the outline of the area. 200 0469 Drydock This code identifies a feature shown by symbols 162(A), 112.68(B), and 512.49(C). These symbols are in two pieces, the manmade shoreline enclosing the water area and the tick-marked gate that is placed in the opening of the drydock. The shoreline is digitized as a line identified by the coincident feature code 209 0005. Place a degenerate line on the point of the V-shaped tick mark. Use this code on both parts of the feature. 3.11.7 Descriptive Attribute Codes Descriptive attribute codes are used to add to or qualify the meaning of another attribute code. A descriptive attribute code is only used with another code: node, line, area, single-point, or general purpose. The use of a descriptive attribute code is, in many cases, called for by the equivalent label on the source. For example, a map may show "sand pits," "gravel pits," "clay pits," or borrow pits." In each case the identifying code for pits (200 0432) must be used with the code to describe the type of pit added; gravel (200 0609), sand (200 0610), clay (200 0611), or borrow (200 0612). 200 0601 Underground This code describes a feature that is labeled "underground." Do not use it to describe a feature that by definition is always underground, such as a mine shaft. 200 0602 Under construction This code describes any feature that is labeled "under construction." 200 0603 Abandoned This code describes any feature labeled "abandoned." 200 0604 Water This code describes a feature that is labeled "water." 200 0605 Oil This code describes a feature that is labeled "oil." 200 0606 Gas This code describes a feature that is labeled "gas." 200 0607 Chemical This code describes a feature that is labeled "chemical." 200 0608 Covered This code describes a pier or wharf that is covered and is shown by symbol 158(A). It is used with code 200 0466. 200 0609 Gravel This code describes a pit labeled "gravel." It is used with code 200 0432. 200 0610 Sand This code describes a pit labeled "sand." It is used with code 200 0432. 200 0611 Clay This code describes a pit labeled "clay." It is used with code 200 0432. 200 0612 Borrow This code describes a pit labeled "borrow." It is used with code 200 0432. 200 0613 Radio This code describes a tower labeled "radio." It is used with code 200 0305. 200 0614 Lookout This code describes a tower labeled "lookout." It is used with code 200 0305. 200 0615 Unincorporated This code describes a locality labeled "unincorporated." It is used with code 200 0410. 200 0616 No population This code describes a locality labeled "unpopulated" or "no population." It is used with code 200 0410. 200 0617 Submerged This code describes any feature labeled "submerged" such as a sewer line (200 0209). Do not use this code on a feature that by definition is underwater, such as a sunken wreck. 200 0618 Ruin This code describes a feature that has the word added to its label, such as the pier or wharf ruin shown by symbol 112.70(B). Do not use this code on ruins described in instructions for code 200 0452. This code is intended for features that are not of the archeological type but are in such a state of decay that they are no longer used for their original purpose. 200 0619 Caliche This code describes a pit labeled "caliche." It is used with code 200 0432. 200 0620 Chert This code describes a pit labeled "chert." It is used with code 200 0432. 200 0621 Cinder This code describes a pit labeled "cinder." It is used with code 200 0432. 200 0622 Pumice This code describes a pit labeled "pumice." It is used with code 200 0432. 200 0623 Shale This code describes a pit labeled "shale." It is used with code 200 0432. 200 0624 Scoria This code describes a pit labeled "scoria." It is used with code 200 0432. 3.11.8 Parameter Attribute Codes 200 0000 Photorevised feature This code is described in section 3.3.3. 202 0--- Width in mils of feature to scale Enter the width in mils, of a linear feature that is shown to scale, in the spaces flush right. 208 0000 Best estimate of position or classification This code is described in section 3.3.3. 209 00-- Coincident feature This code is described in section 3.3.3.