ATT
ACCESS_RESTRICTION

This attribute describes access restrictions on a road.  Examples include toll roads and private roads.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
AGENCY

Codes identifying the administering agency for federal land.  This attribute is only used on 1:2,000,000-scale DLG's and 1:100,000-scale DLG's authorized for federal lands.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
AHUPUAA

Ahupuaa (Hawaii.)  This attribute identifies 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.  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
AMENDED

This attribute identifies a contour element added by interpolation after map compilation and is limited to contour segments added or modified to correct compilation errors.  An amended contour is assumed to be a standard index or intermediate contour by default unless qualified by additional attributes, such as SUPPLEMENTARY.  The application of this attribute is very conservative and is restricted to those areas where it is imperative to correct a minor compilation error in order to make the hypsographic file logical.  This attribute should not be used over extensive problem areas, where it would be preferable to revise and recompile the contour separate.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
APPROXIMATE

This code identifies contours in areas where accurate representation is not attainable through normal compilation procedures.  Examples are areas of dense vegetation cover and marsh land.  Approximate contours are shown by symbols 303, 304 (A); 112.89, 132.3, 141.43 (B); or 532.3(C).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
APPROXIMATE_POS

Approximate position.  This code should be used whenever dashed land lines are shown on the map, indicating that the lines do not meet NMAS, but can be positioned within 0.1 inch at map scale.  Boundaries of grants that are labeled as "approximate" also are assigned this code.  If only a portion of a grant is approximate, this code is assigned from the nearest found grant monument along the labeled segments of the line.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
ARBITRARY_EXT

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
BANK

This attribute describes the limit of a double-line feature, such as a stream, as if one were facing downstream.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
BANNER            

Descriptive text contained in DLG-3 optional format files which often contains information on the software which produced the optional format file.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
BEST_ESTIMATE

This indicates that the position and (or) classification of the feature is not sufficiently clear to warrant unqualified use of the attribute code assigned.  This code identifies hypsography depicted in areas of dense or complex relief where the value of a given contour cannot be absolutely determined from the source material.  This attribute is used in conjunction with an elevation parameter attribute.  In areas where contour feathering occurs, elevations for the feathered segments can generally be determined by referring to the compilation specifications for feathered areas.  These specifications state that the last contour segment dropped in a constricted area is the first one to begin again as soon as space is available.  The compilation specifications also state that when the space between index contours limits the showing of intermediate contours, the intermediate contours are compiled following the order of retention rule, which states the priority for portrayal as follows:  the highest intermediate, the lowest, the second highest, and the second lowest.  Only when the elevation cannot be clearly determined by using these guidelines is the BEST_ESTIMATE attribute also applied to the contour segments carrying an estimated elevation.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
CITY

Incorporated city, village, town, borough, or hamlet.  This attribute identifies an area delineated by symbols 206(A), 112.77(B), 512.127(C), or 2107.04(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
CIVIL_TOWNSHIP

Civil township, district, precinct, or barrio.  This attribute identifies an area delineated by symbols 205(A), 112.77(B), 512.126(C), or 2107.03(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
CODED_FLAG        

Data Base Coded Edge Flag.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
COINCIDENT

This attribute 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 value of this attribute.  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
COUNTY

County or county equivalent (e.g., parish, independent city) FIPS code.
FIPS
FIPSPUB 6-3, Counties, and County Equivalents of the States of the United States and District of Columbia, 15 Dec 79.
ATT
COUNTY_SEAT

This code describes a locality which is the seat of county administration.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
COVERED

This describes a feature which is labeled "covered."
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
DATE_QUALIFIER    

Date qualifier- Qualifier to discriminate revision date.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
DEPRESSION

This code identifies contours surrounding a basin or sink denoted by right-angle ticks (hachures) pointing inward (downslope).  Depression contours are shown by symbols 307(A); 112.90, 132.6, 132.7, 133.2 (B); 532.6, 532.7 (C); or 2302.04(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
DRY

This describes any feature that is labeled "Dry," such as a dry lake, shown by symbol 134.7(B), or dry well.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EARTHEN

This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EDGEER            

Reason for EDGEES status flag.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EDGEES            

Quality Control Status Flag for east edge as compared to an adjoining DLG file.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EDGENR            

Reason for EDGENS status flag.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EDGENS            

Quality Control Status Flag for north edge as compared to an adjoining DLG file.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EDGESR            

Reason for EDGESS status flag.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EDGESS            

Quality Control Status Flag for south edge as compared to an adjoining DLG file.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EDGEWR            

Reason for EDGEWS status flag.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
EDGEWS

Quality Control Status Flag for west edge as compared to an adjoining DLG file.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
ELEVATION

Altitude of a feature (such as contour, spot elevation, control point, or water surface) above the vertical datum.  Negative values indicate values below datum.  Negative contour elevations are only found on maps of certain parts of the United States that portray contours below datum, such as New Orleans.  This attribute 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 attribute 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
FEDERALLY_ADMIN

Indicates that the land is administered by the United States goverment.  This attribute is only used on 1:2,000,000-scale DLG's and 1:100,000-scale DLG's authorized for federal lands.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
GLACIER_OR_SNOW

This code identifies hypsography in areas covered by glaciers or snow fields.  It identifies contours within areas outlined by symbols 428, 429 (A); 141.27, 141.28 (B); 541.43, 541.44 (C); or 2205.04(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
HAWAIIAN_HOMESTEAD

Hawaiian homestead.  This code identifies 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.  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
HISTORICAL

This indicates a feature which is of historical importance.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
ID_IN_FIELD

Corner identified in the field.  This code corresponds to "existent" corners as defined in the Bureau of Land Management's Manual of Instructions for the Survey of the Public Lands (1973).  It indicates that physical evidence of the corner was recovered during field operations.  Such a corner is shown by a double-weight (0.01 inch) cross or "T" on symbols 506, 507 (A); 523.5, 523.6 (C); or 2502.07, 2502.08 (D) on the published map.  Note that all meander (300 0004), witness (300 0007), and quarter-section (300 0012) corners  also bear this attribute, because they are only mapped if recovered.  On some older maps, a single-weight (0.005 inch) cross or "T" denotes an indicated corner.  Such corners do not receive this attribute.  The code is also used in conjunction with the land grant corner (300 0014) when a found land grant monument, symbols 501(A), 523.11(C), or 2502.02(D), is depicted.  When a land grant is coincident with a boundary, the boundary symbol takes precedence.  If, however, a recovered monument was established to mark the grant boundary, it is shown by symbol 501 on the red plate and is coded as a found grant corner.  Monuments shown by symbols 226(A) or 512.105(C) on the black plate are boundary monuments and are captured in the boundaries category.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
INTERMITTENT

This attribute 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 overrides the default value of "perennial" that is assumed if this attribute is not applied.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
INTERPOLATED

This identifies a water surface elevation that is not printed on the graphic source but has been interpolated from adjacent hypsography.  If necessary, a default value equal to one-half of the contour interval is subtracted from the closest contour completely above the hydrographic feature.  Interpolated elevations are applied when required to perennial and intermittent lakes, ponds, reservoirs, and other impounded bodies of water meeting a minimum size of 0.50 inch at map scale.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
IN_DISPUTE

This is applied to any federally administered land whose jurisdiction is in dispute.  This attribute is only used on 1:2,000,000-scale DLG's and 1:100,000-scale DLG's authorized for federal lands.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
IN_SNOWSHED

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
JUXTAPOSITION

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
LAND_GRANT

Land grant identifier.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
LANES

This code is used to encode the number of lanes annotated on a road on the source map.  Use this code on all segments of a road to which the annotated number of lanes applies.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
LIMITED_ACCESS

This describes a road that is determined to be a limited access road.  A limited access road is one whose function is to provide a "high speed" route between major cities or destinations, bypassing smaller places.  This type of road is distinguished by the presence of interchanges with other roads rather than intersections, and, on some, the presence of service areas.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
L_PB_INTERVAL     

Largest primary bathymetric interval.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
L_PRIM_INTERVAL   

Largest primary contour interval.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
MINERAL_OR_HOT

This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
MONUMENT_NUMBER

Land grant or boundary monument numbers.  On some large land grants, monuments were established along the boundaries of the grant in addition to monuments at the grant corners.  The value of this attribute is the number of the monument and cannot be equal to 0.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
NARROW_GAUGE

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
NATIONAL_CAPITAL

This code describes a locality which is the capital city of a nation.  This code is only used for 1:2,000,000- scale DLG's.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
NATIONAL_FOREST

National forest or grassland.  This attribute identifies a national forest or grassland delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
NAVIGABLE

This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
NE_LATITUDE       

Latitude value of the north-east corner of the quadrangle.
FIPS
FIPSPUB 70-1 Representation of Geographic Point Locations for Information Interchange
ATT
NE_LONGITUDE      

Longitude value of the north-east corner of the quadrangle.
FIPS
FIPSPUB 70-1 Representation of Geographic Point Locations for Information Interchange
ATT
NO_POPULATION

This code describes a locality labeled "unpopulated" or "no population."  It is used with code 200 0410.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
NW_LATITUDE       

Latitude value of the north-west corner of the quadrangle.
FIPS
FIPSPUB 70-1 Representation of Geographic Point Locations for Information Interchange
ATT
NW_LONGITUDE      

Longitude value of the north-west corner of the quadrangle.
FIPS
FIPSPUB 70-1 Representation of Geographic Point Locations for Information Interchange
ATT
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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
NUCLEAR

This code describes a power plant that is labeled "nuclear."
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
OPERATIONAL_STATUS

This attribute describes the status of the operation of the feature.  For example, features can be under construction or abandoned.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
ORIGIN_OF_SURVEY

Two-digit code indicating origin of survey.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
QUAD_NUMBER       

Arbitrary quad number(24k files) - Quad number assigned for USGS/NMD internal use.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
PHOTOREVISED

This attribute identifies a map feature obtained by photorevision methods and printed in purple on 1:24,000- and 1:25,000-scale maps.  The photorevised attribute can be applied to any feature type but can not be used alone except as a line code for a photorevised line in the boundary category.  The photorevised attribute 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
POPULATION_CLASS

Classification into 7 classes of the population of localities.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
PRODUCT

Material produced by a well, mine, or pit.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
PROTRACTED_POS

Protracted position.  The Bureau of Land Management has defined protracted land lines for all areas of Alaska not yet subdivided by ground surveys and some other areas in the continental United States.  The unsurveyed land lines represent theoretically perfect subdivisions.  Protracted land lines are shown as solid  gray  lines  for  all  new  and  revised  Alaska  maps.    The  protracted  land  lines  for  all  suspended  and  unsurveyed  townships  in  the  conterminous United States, are not shown on 1:24,000-scale but are shown on 1:100,000-scale maps by symbols 123.3 and 123.4 (B).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
RANGE

Range number.  The last character is either "E" or "W", indicating east or west of the principal meridian.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
RAPID_TRANSIT

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."
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
RELATION_TO_GROUND

This attribute describes the relationship of a feature to the ground surface.  Examples include features which are underground, elevated, or in tunnels.  This does not describe the relationship between features (see VERTICAL_RELATIONSHIP.)
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
RIVER_MILE

This attribute contains the mile value of 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.  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
ROAD_WIDTH

The ground width in feet of a road that is scribed to scale rather than shown by the standard size symbol on 1:24,000-scale maps.  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
ROTATION_ANGLE

The angle of rotation is defined as the smallest clockwise angle measured between the north line that passes through the center of the symbol and any edge of the symbol.  Cave or mine tunnel entrances (2000302) also require an angular rotation parameter code.  This angle is measured between the north line passing through the intersection of the arms and the symbol shaft.  This attribute is no longer being collected in DLG-3 files but may exist in older DLG-3 files.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
ROUTE_NUMBER

Interstate, U.S., state, reservation, or county route number of a road.  This includes any alphabetic portion of a route number.  The route number begins with a jurisdiction identifier:  "I " for Interstate, "US " for U.S., "SR " for state, "RR " for reservation, "CR " for county.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
ROUTE_TYPE

This attribute contains route qualifiers such as "Alternate" and "Business".
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
S_PB_INTERVAL     

Largest primary bathymetric interval.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
S_PRIM_INTERVAL   

Smallest primary contour interval.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
SALT

This attribute describes any feature, such as a marsh or well, that is labeled "salt."
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
SE_LATITUDE       

Latitude value of the south-east corner of the quadrangle.
FIPS
FIPSPUB 70-1 Representation of Geographic Point Locations for Information Interchange
ATT
SE_LONGITUDE      

Longitude value of the south-east corner of the quadrangle.
FIPS
FIPSPUB 70-1 Representation of Geographic Point Locations for Information Interchange
ATT
SECTION

Section number, including any alphabetic portion.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
SPOT_CATEGORY

DLG-3 category associated with a spot height not at ground elevation (0200301)
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
SOURCE_DATE

Year of the original source material.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
STATE

State or State equivalent FIPS code.
FIPS
FIPSPUB 5-2, States and Outlying Areas of the United States, 28 May 87.
ATT
STATE_CAPITAL

This code describes a locality which is the capital city of a state.  This code is only used for 1:2,000,000-
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
SUPPLEMENTARY

This attribute identifies contours added between intermediate contours at the time of map compilation to aid in defining topography in areas of minimal slope.  Supplementary contours are shown by symbols 302(A); 112.1, 133.1, 133.2 (B); 533.1(C); or 2302.01(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
SW_LATITUDE       

Latitude value of the south-west corner of the quadrangle.
FIPS
FIPSPUB 70-1 Representation of Geographic Point Locations for Information Interchange
ATT
SW_LONGITUDE      

Longitude value of the south-west corner of the quadrangle.
FIPS
FIPSPUB 70-1 Representation of Geographic Point Locations for Information Interchange
ATT
SUBMERGED

This 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 attribute is not used to define water channels. (0500419).  It is also used to describe features labeled "sunken."  The outline of the submerged river course is generally digitized as an unattributed line.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
TOWER_TYPE

The purpose of a tower, such as radio or lookout.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
TOWNSHIP

Township number.  The last character is either "N" or "S", indicating north or south of the base line.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
TOWNSHIP_CODE

Civil township or township equivalent FIPS code.
FIPS
FIPSPUB 55-1, Guideline:  Codes for Names of Populated Places, Primary County Divisions, Other Locational Entities in the United States, 30 Dec 83.
ATT
TRACKS

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).  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
UNDERWATER

This code identifies submerged contours compiled before an area was inundated by the construction of a dam.  These areas are overprinted with blue tint.  The code is not used on contours overprinted with areas of purple added through the photorevision process.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
UNIMPROVED

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
UNINCORPORATED

This code describes a locality labeled "unincorporated."  It is used with code 200 0410.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
UNSURVEYED

This attribute describes stream features shown by symbols 408(A), 141.5(B), or 2202.05(D) which indicates a stream is unsurveyed, or to any other feature that is labeled "unsurveyed."
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
VERTICAL_DATUM

Datum used for elevation attribute values.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
VERTICAL_RELATION

This attribute describes the vertical relationship of a feature to another feature.  Examples are features which overpass or underpass other features.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
WIDTH

The width in mils in map units, of a linear feature that is shown to scale.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
WILDERNESS_AREA

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
WITH_ELEVATION

Corner with elevation value.  This attribute is used when a vertical control station, elevation third order or better (bench mark), is coincident with a found section corner.  The found corner symbol, marked by the label "BM" and an elevation value symbol 230 (A) is used to depict this condition.  The presence of a spot elevation at a corner (symbol 224 (A)) does not warrant the use of this code.  The code is intended to signify inclusion in a control network as an aid in integration with vertical control data.  This attribute is no longer used in DLG's.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
WITH_HORIZONTAL

Corner with horizontal control.  This attribute is used when a horizontal control station is coincident with a found section corner.  The horizontal control station symbol is shown on the black plate by symbol 229 (A).  This attribute is no longer used in DLG's.
USGS/NMD
United States Geological Survey/National Mapping Division
ATT
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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200200

Contour, including index and intermediate contours depicting standard contour intervals and supplementary contours.  They are designated by symbols 300, 301 (A); 132.1, 132.2 (B); 532.1, 532.2 (C); or 2302.01, 2302.02 (D).  Line segments added to join breaks at contour labels are given identical codes of the appending contours and, therefore, do not require unique coding.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200201

Carrying contour.  A portion of a contour at cliff embankments and similar features where multiple contours merge into a single line.  The carrying contour is digitized as a separate line segment.  Carrying contours are given the parameter elevation attributes for all contours joined to the nodes of the carrying contour segment.  Carrying contours are shown by symbols 306(A), 132.5(B), 532.5(C), or 2302.03(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200203

Continuation contour.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200205

Bathymetric contour, a line connecting points of equal water depth.  The datums include various mean low water levels for tidal areas, mean low water surface levels for inland water bodies, and stream gradient for navigable rivers above tidal reaches.  Bathymetric contours are shown by symbols 112.87, 112.88, 141.41, 141.42 (B) or 512.147, 512.148, 541.60, 541.61 (C).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200206

Depth curve.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200207

Watershed divide.  This entity identifies major watershed divides such as the Continental Divide and the Tennessee Valley Divide.  These features are designated by symbols 132.15(B) or 532.16(C) and may be coincident with features of other categories.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200208

Closure line.  This entity is also used to define the perimeter of areal features, such as void areas, that are not otherwise explicitly symbolized.  Elevation parameters are not added to closure lines.  The purpose of this feature is to preserve topological relationships.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200299

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 entity represents lines digitized to segment the data within a file to create more background areas, thereby enabling large files to be processed.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200300

Spot elevation, less than third order.  This entity identifies points marked with symbols 224(A), 112.41(B), 512.108(C), or 2102.10(D).  It indicates an elevation established by using less than third-order control methods.  For example, the elevation on a summit established by photogrammetric means would have this code.  Spot elevations should be collected at every occurrence (all maps) unless marked overcrowding of spot elevations exists. Spot elevations coincident with coded point features from other categories require the use of the COINCIDENT attribute.  For example, a spot elevation on a horizontal control station, shown by symbols 216(A), 512.99 (C), or 2102.03(D), would be coincident with the Survey Control and Markers category.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0200301

Spot elevation, less than third order, not at ground level.  This identifies points marked with symbols 224(A), 112.41(B), 512.108(C), or 2102.10(D).  It indicates an elevation established by using less than third-order control methods and located on features that are not at ground level, such as bridges or levees that are not symbolized with contours.  These elevations are encoded uniquely so they may be isolated from other elevations used for Digital Elevation Model gridding or automatic contour tagging.  This code is used in conjunction with the ELEVATION attribute and the SPOT_CATEGORY attribute.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500001

Upper origin of stream.  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500002

Upper origin of stream at water body.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500003

A sink, the definite point where a stream flows underground, shown by symbols 407(A), 141.8(B), 541.12(C), or 2202.04(D).  This is used to identify a node placed at the point of disappearance.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500004

Stream entering water body.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500005

Stream exiting water body.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500100

Alkali flat, an area shown by symbols 450(A), 141.16(B), 541.28(C), or 2203.08(D) and labeled.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500101

Reservoir that is shown by symbols 179, 413 (A); 112.6, 141.12, 141.13, 145.2 (B); 512.61, 541.24 (C); or 2203.09(D) and labeled or named as a reservoir.  This is not used to identify features related to sewage treatment, fish farming, or water filtration.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500102

A reservoir area shown by symbol 180(A); 512.62, 545.6 (C); or 2106.08(D) and named or labeled as a reservoir.  This feature does not appear on 1:100,000-scale maps.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500103

Glacier or snowfield.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500104

Salt evaporator.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500105

Inundation area.  This identifies the area of land between the normal operating level and the high water line in reservoirs or lakes impounded by dams.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500106

Fish hatchery, fish farm, or fish pond.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500107

Industrial water impoundment.  This is 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500108

Area to be submerged.  This is 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.  If an elevation is associated with the shoreline that defines the limits of this area, the elevation is encoded by using the appropriate parameter code on the shoreline element.  Other features within the area will have separate attribute primary module records in order to identify their enityt type.  This entity is used when a dam is under construction and the limits of the intended reservoir are known.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500109

Sewage disposal pond or filtration plant.  This identifies 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 entity is also used for 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500110

Tailings pond or settling basin.  This identifies 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."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500111

Marsh, wetland, swamp, or bog.  This identifies any area shown by symbols 431(A), 143.1(B), 543.1(C), or 2205.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500112

Mangrove area.  This identifies an area shown by symbols 437(A); 144.1, 152.4 (B); 544.1, 552.4 (C); or 2205.08, 2402.06 (D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500113

Rice field.  This identifies 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.  This entity does not appear on 1:100,000-scale maps.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500114

Cranberry bog.  This identifies 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."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500115

Flats (tidal, mud, sand, or gravel.)  This 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 0500423), or beach areas on dry land.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500116

Bays, estuaries, gulfs, oceans, or seas.  This 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 (0500202).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500117

This identifies a shoal area shown by symbols 243(A), or 512.142(C) and labeled "Shoal."  This feature does not appear on 1:100,000-scale maps.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500118

Soda evaporator.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500119

This identifies an area labeled "Duck Pond."  This feature is shown by symbols 141.17, 146.2 (B) or 541.29, 546.2 (C).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500121

Obstruction area in water area.  This 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 therefor the area is not double-coded.  Arbitrary closure lines are required to complete the definition of an open-ended area.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500200

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.  This is also used to define the shorelines of double-line streams and ditches.  This is also used to identify the shoreline of islands, lakes, and reservoirs that are digitized as degenerate lines.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500201

Manmade shoreline.  This 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 is also used to identify the shoreline of islands, lakes, and reservoirs that are digitized as degenerate lines.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500202

Closure line.  This 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 also identifies a line segment used to close gaps in streams where the symbol has been broken.  A closure line is used to define the extent of a void area that is not otherwise symbolized.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500203

Indefinite shoreline.  This identifies a line shown by symbols 401(A), 415(A), 141.3(B), 541.3(C), or 2203.02(D), which indicates that the shoreline cannot be definitely established.  This symbol is not to be confused with an intermittent shoreline shown around intermittent ponds and dry lakes on 1:24,000-scale quads compiled prior to December 1985.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500204

Apparent limit.  This identifies a line digitized around various features represented by an areal pattern when a definite outline does not exist.  The edge of the pattern (such as marsh or wash) is followed as closely as possible and is given this entity label to indicate the arbitrary nature of the line.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500205

Outline of a Carolina bay.  This 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 ditches, is digitized as a separate feature.  If a bay outline is a complete and closed ellipse, the interior area does not have attributes unless it is a hydrologic feature in its own right.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500206

Danger curve.  This identifies a line shown by symbol 244(A), which represents the limit of an area considered to be dangerous for navigation.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500207

Apparent shoreline.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500208

Sounding datum.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500209

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 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500299

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 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500300

Spring.  This is 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500301

Nonflowing well.  This 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 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."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500302

Flowing well.  This identifies a feature shown by symbols 426(A), 141.26(B), 541.39(C), or 2205.02(D) and labeled "Flowing well".  This may also be used on a node when the well symbol occurs directly on a line that is being digitized in the hydrographic overlay.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500303

This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500304

Geyser or vent.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500305

Windmill.  This identifies a point placed on a well shown by symbols 199(A), 112.3(B), 512.69(C), or 2111.04(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500306

Cistern.  This identifies a feature shown by symbols 426(A), 141.26(B), 541.39(C), or 2205.02(D) and labeled "cistern."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500400

Rapids.  This 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 entity label 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 (0500202) 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."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500401

Falls.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500402

Gravel pit or quarry filled with water.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500403

Gaging station.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500404

Pumping station.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500405

Water intake.  This 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 entity does not appear on 1:100,000- scale maps.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500406

Dam or weir.  This 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 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 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500407

Canal lock or sluice gate.  This 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 depending on the size of the feature.  Symbols 160(A) or 2108.08(D) is digitized as a node on the single-line stream.   Symbols  161(A)  or  2108.09(D)  are  digitized as  a  line  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 entity 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500408

This 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 entity label 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 entity label and the elevation value are assigned to a node placed on the digitized shoreline near the label.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500409

Gate (flood, tidal, head, or check.)  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500410

This 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), they area digitized as an area.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500411

Crevasse (glacial.)  This 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 0500204).  This entity does not appear on 1:100,000-scale maps.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500412

Stream.  This identifies all naturally flowing water except braided streams (see 0500413).  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.  In some cases an appropriately symbolized natural stream course will carry a ditch label; however, do not code as ditch.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500413

This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500414

Ditch or canal.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500415

Aqueduct.  This 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 attribute for tunnel in addition to the aqueduct code.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500416

Flume.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500417

Penstock.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500418

Siphon.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500419

Channel in water area.  This identifies a feature shown by symbols 444(A); 141.34, 112.94 (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 entity 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 entity does not apply to submerged river courses in inundated areas.  On 1:100,000-scale maps use this entity label to identify an airboat trail, canoe trail, or wilderness waterway shown by double line symbol 112.94(B) or by the single line symbol corresponding to 541.16(C).  (This symbol is not listed in the 1:100,000- scale symbol book.)
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500420

Wash or ephemeral drain.  This 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 entity label 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), 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 Nonvegetative Features data category.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500421

Lake or pond.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500422

Coral reef.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500423

Sand in open water.  The 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500424

Spoil area, dredged area, or dump area.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500425

Fish ladder.  This 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 entity label.  A fish ladder, that is symbolized as a labeled portion of a stream feature, is not double coded with the stream entity.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0500426

Holiday area.  This 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0700101

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0700102

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0700103

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0700104

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0700105

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0700200

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0700201

Edge of surface cover at built-up, house-omission, or urban area.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0700299

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0800100

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.  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0800101

Gravel beach.  This code identifies an area shown by the gravel pattern USGS/NMD 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/NMD 17 and the only distinction made between them is the label "gravel."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0800102

Sand area or beach.  This code identifies an area shown by the sand pattern, USGS/NMD 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."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0800103

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/NMD 17A, which is no longer in use.  Such areas are also identified by this code.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0800104

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0800200

Closure line.  This code describes a line digitized to define the perimeter of void areas that is not otherwise explicitly symbolized.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0800299

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0800300

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900001

Monumented point on a boundary.  This code describes a physical monument lying on a boundary line.  This includes any of the following:  (1) 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).  (2) Survey control stations on a boundary.  These monuments are designated by symbols  216 through 219, 222, 223, 225 through 227, 230 through 231 (A); 512.99 through 512.107 (C); or 2102.02 through 2102.04, 2102.06 through 2102.09, 2102.12 (D).  (3) Land grant monuments on a boundary.  These monuments are designated by symbols 501(A) or 2502.02(D).  Land grants are digitized as part of Public Lands.  (4) Any other point represented with a red or black boundary monument symbol.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900103

National park, monument, lakeshore, seashore, parkway, battlefield, or recreation area.  This identifies 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900105

National wildlife refuge, game preserve, or fish hatchery.  This identifies a wildlife recreation 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900107

Indian reservation.  This code identifies 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900108

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900109

Nonmilitary government reservation.  This code is no longer used in DLG-3 files, having been replaced by 0900111 and 0900129.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900110

Federal prison delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900111

Miscellaneous Federal reservation.  This code identifies 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, Nonmilitary Government Reservation.  The area is delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900113

Land grant.  Land grants are presently collected in the Public Land Survey theme as entity 3000103 but some older Boundary data may use this entity.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900129

Miscellaneous State reservation.  This code identifies 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900130

State park, recreation area, arboretum, or lake.  This code identifies a State park, recreation area, arboretum, or lake delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900131

State wildlife refuge, game preserve, or fish hatchery.  This code identifies a State wildlife refuge, fish hatchery, or game preserve delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900132

State forest or grassland delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900133

State prison area delineated by symbols 207(A), 112.78(B), 512.128(C), or 2107.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900134

County game preserve delineated by symbols 207, 209 (A); 512.128, 512.129 (C); or 2107.05, 2107.06 (D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900150

Large park (city, county, or private.)  This code identifies a regional, city, county, or private park delineated by symbols 207(A), 112.79(B), 512.128(C), or 2107.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900151

Small park (city, county, or private.)  This code identifies regional, city, county, or private park delineated by symbols 209(A), 512.129(C), or 2107.06(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900197

Canada.  This code identifies an area inside 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900198

Mexico.  This code identifies an area 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900199

Open water.  This code identifies water areas on coastal quadrangles, which are not otherwise included within a coded area, such as State FIPS.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900201

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900202

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900203

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900204

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900299

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
0900301

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500200

Closure line.  This code describes a line digitized to define the perimeter of void areas.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500300

Horizontal control station, third order or better, permanent mark.  This code identifies 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500301

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500302

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500303

Horizontal control station, checked spot elevation.  This code identifies 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500310

Vertical control station, third order or better, tablet.  This code identifies 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500311

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500320

Boundary monument, third order or better, tablet.  This code identifies 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 boundary category.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500321

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 boundary category.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500330

Reference monument.  This code identifies a reference monument shown by symbols 226(A) or 512.105(C).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500331

U.S. mineral or location monument.  This code identifies 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1500332

Other control point.  This code identifies any other control point as shown by symbols 231(A) or 512.013(C).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700001

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700002

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700004

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700005

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 0.030 inch in diameter, it is digitized as a node and assigned this code.  When the feature is 0.030 inch or greater 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 digitized 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700006

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700007

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700201

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700202

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700203

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700204

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700205

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.)
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700206

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.)  This code does not apply to 1:100,000-scale maps.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700207

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.)
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700208

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.)  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700209

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700210

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700211

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700212

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700213

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700214

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700215

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700217

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700218

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700219

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700220

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700221

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700222

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700299

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700401

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700402

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700403

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700404

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700405

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 0.60 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700406

Covered bridge.  This entity is no longer collected in DLG-3 data but may exist in some older data.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700604

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1700613

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800001

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800002

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800003

Crossover.  This code identifies a digitized node placed on a central point of the diagonal line connecting two railroad tracks that indicates a crossover point.  Do not use this code to identify features inside a railroad yard.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800007

Drawbridge.  This code identifies a node that is digitized in the center of the circle portion of the drawbridge 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800201

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800202

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800204

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800205

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800207

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800208

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800209

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800210

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800211

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800299

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800400

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.  An angular rotation parameter code (183.0__) is required in the case of 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800401

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1800402

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900001

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900002

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900003

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900004

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900201

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900202

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900203

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900204

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900205

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900206

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900299

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900300

Seaplane anchorage.  This code identifies a seaplane anchorage shown by symbol 36 in symbols for 1:50,000-scale 15-minute Quadrangle Topographic Maps of the United States, Appendix II, July 1980, p. ii-4.  The degenerate line is digitized at the mid-point of the shaft of the anchor.  This code is not currently used.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900400

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900401

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900402

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900403

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900404

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900405

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900406

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 Structures category.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900407

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
1900408

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000001

End point of linear mandmade feature.  This entity no longer is used in DLG-3 files but may exist in older files.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000002

Point on linear manmade feature.  This entity no longer is used in DLG-3 files but may exist in older files.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000100

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000101

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000102

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000103

Orphanage.  This code identifies a large class 1 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000104

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 boundary category.  When the area contains individual buildings see codes 200 0409 and 200 0400.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000105

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000120

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000122

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000123

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 codes 200 0400 and 200 0401).  If it is not possible to distinguish the outline, then digitize a degenerate line on the first letter of the golf course label.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000124

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000125

Zoo.  This code identifies an area that is labeled as a zoo, zoological park, or wild animal park.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000126

Drive-in theater.  This code identifies an area defined by symbol 252(A), 512.68(C), or 2111.08(D).  The interior structures are digitized and coded (see codes 200 0400 and 200 0213).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000127

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, 200 0401, and 200 0214).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000128

Playground.  This code identifies an area labeled "playground."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000140

Marina.  This code identifies an area labeled a "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 0401).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000141

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000150

Built-up, urban, or house omission area.  This code identifies a built-up, urban, or house omission area delineated by symbols 520(A), 115.1(B), 515.1(C), or 21101.(D).  It does not include those areas normally cleared within an urban area such as parks, cemeteries, colleges, schools, and hospitals with grounds equal to or larger than, an average city block on the map.  Do not code the outline as coincident with transportation because the edge of the tint area does not coincide with the centerline of a road, which is the line digitized in the transportation category.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000160

Industrial park.  This code and codes 200 0161 and 200 0162 identify areas labeled to indicate a particular industrial feature.  On 1:24,000-scale source the area may contain both class 1 and 2 buildings of various sizes shown by symbols 163-165, 174-176 (A) or 2106.01 through 2106.03 (D).  Do not use these codes for tank farms or oil and gas fields.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000161

Materials storage area.  This code and codes 200 0160 and 200 0162 identify areas labeled to indicate a particular industrial feature.  On 1:24,000-scale source the area may contain both class 1 and 2 buildings of various sizes shown by symbols 163-165, 174-176 (A) or 2106.01 through 2106.03 (D).  Do not use these codes for tank farms or oil and gas fields.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000162

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 both class 1 and 2 buildings of various sizes shown by symbols 163-165, 174-176 (A) or 2106.01 through 2106.03 (D).  Do not use these codes for tank farms or oil and gas fields.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000163

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."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000164

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000165

Oil sump or sludge pit.  This code identifies an area shown by symbols 250(A), 512.86(C), or 2111.07(D) and labeled.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000180

Tank farm.  This code identifies an area labeled "tank farm" that encompasses a group of tanks shown by symbols 196(A), 197(A), 112.2(B), or 2111.02(D).  The tanks in the interior of the area are also digitized (see code 200 0425).  The tank farm outline, if not clearly demarcated, is obtained by digitizing a line around the outermost tanks.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000181

Feedlot.  This code identifies an enclosed area labeled "feedlot," shown by symbol 2111.14(D).  The area may contain individual buildings.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000182

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 codes 200 0400 and 200 0401.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000183

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 0401).  The outline of the area may be coincident with a military reservation boundary.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000184

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 0401).  The outline of the area may be coincident with a military reservation boundary.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000200

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000201

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), the width attribute is used to encode the width.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000202

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 attribute WIDTH 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000203

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000206

Fence line.  This code identifies a line shown by symbols 522(A), 523.15(C), or 2110.07(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000207

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000209

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000211

Coke ovens.  This code identifies a centerline digitized along symbols 253(A) or 512.70(C).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000212

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000213

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000214

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000215

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000250

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000299

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000300

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000301

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000302

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000303

Mine shaft.  This code identifies a feature shown by symbols 186(A), 112.36(B), 512.81(C), or 2109.05(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000304

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000305

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000306

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000307

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000308

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000309

Light.  This code identifies a feature shown by symbols 198(A), 112.102(B), 512.163(C), or 2111.15(D) and labeled "Light."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000310

Brick kiln.  This code identifies a feature shown by a circle 0.03 inches in diameter that is labeled "brick kiln."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000311

Drill hole.  This code identifies a feature shown by symbols 198(A), 112.101(B), or 2111.03(D) and labeled "drill hole."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000312

Watermill.  This code identifies a watermill shown by symbol 28 in Symbols for 1:50,000-scale 15-minute Quadrangle Topographic Maps of the United States, Appendix II, page II-3.  This code is not currently used.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000313

Anchorage.  This code identifies an anchorage shown by symbol 118 in Symbols for 1:50,000-scale 15-minute Quadrangle Topographic Maps of the United States, Appendix II, page II-11.  This code is not currently used.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000314

Guzzler.  This code identifies a feature shown by symbols 198(A), or 2111.03(D) and labeled "guzzler."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000315

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000316

Campsite.  This code identifies a feature shown by symbol 512.72(C) and labeled.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000317

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."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000400

Building.  This code is currently 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).  Prior to 1991, this code was only used to identify a class 1 building, that is, a structure intended primarily for housing human activities.  A class 1 building is shown by symbols 163, 164, 165 (A); 112.1(B);  512.52,  512.53 (C);  or  2106.01  through 2106.03 (D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000401

Class 2 building.  This code identifies a class 2 building, that is, a structure intended to house machinery or animals or for storage.  A class 2 building is shown by symbols 175, 176 (A) or 512.57, 512.58 (C).  Class 2 buildings are not shown on 1:100,000-scale maps nor are building classifications completed on Provisional Edition Maps.  This code is not used on a class 2 building that has a specific code, such as a sewage disposal plant.  It is used, however, on class 2 buildings that in themselves have no other specific code but are located within a coded area.  One example is a building within a zoo.  This code is only used in DLG's collected before October 1991.  This code is no longer used.  All first and second class buildings are currently given the code 2000400 and are not differentiated.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000402

Church.  This code identifies a class 1 building shown by symbols 168-170(A), 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 (code 200 0100).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000403

School.  This code identifies a class 1 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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000404

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000405

Courthouse.  This code identifies a building labeled as a courthouse, regardless of jurisdiction.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000406

Post office.  This code identifies a building labeled as a post office.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000407

City or town hall.  This code identifies a building labeled as a city or town hall.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000408

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000409

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000410

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000411

Amphitheater.  This code identifies a structure generally symbolized by a 0.003-inch solid outline that is compiled to scale and labeled.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000412

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000420

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000421

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000422

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000423

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000424

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000425

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000426

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000427

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000428

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000429

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000430

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000431

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000432

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 (see codes 200 0609 through 200 0612).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000433

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 the class of building, as described in code 200 0400 or 200 0401, and identify each with this code.  Do not use this code for a radio tower (see code 200 0305).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000434

Storage bin.  Storage bins may be symbolized as tanks or as buildings, but with the label "storage bin" or "silo."  The feature is digitized according to the instructions for codes 200 0425 or 200 0400, as appropriate, and identified with the code.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000435

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000436

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000438

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000445

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000446

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000447

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000448

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000449

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 the symbol.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000450

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 boundary 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000451

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000452

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 dasshed if the symbol is less than 0.05 by 0.05 inch in size (both in reference A and reference B).  This code also escribes an Indian mound that is shown by contours and a name or label.  An unattributed line is digitized to define he 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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000453

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 3.6).  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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000454

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000455

Port of entry.  A port of entry is a class 1 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 class 1 buildings (see code 200 0400).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000456

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 class 1 building and labeled.  In such cases digitize the building as an area and give it this code.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000465

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000466

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).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000467

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000468

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
2000469

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000001

PLSS section corner.  This point exists at an extremity of a section boundary and wherever two section lines meet or cross.  It is normally surrounded by three or four distinct sections.  This code includes standard corners (on a standard parallel or base line) and township corners (at an extremity of a township boundary).  Found section corners are shown by symbols 506(A), 523.5(C), or 2502.07(D).  Indicated section corners may be shown by symbol 506(A).  Unfound corners are not explicitly  symbolized.    This  code  is  also  used  for section corners that are not symbolized because of feature coincidence, such as  a corner at a road intersection.  Corners coincident with a boundary also carry code 309 0009 (coincident with monumented point on boundary, 90 0001).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000002

Point on section line.  This code is no longer used in DLG's.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000003

Closing corner.  This is a corner established at the intersection of a surveyed line with a previously established boundary at a point between corners.  It is shown by symbols 507(A), 523.6(C), or 2502.08(D).  In general, there are three cases of the occurrence of closing corners:  Error introduced into the rectangular system because of the convergence of meridians is taken up at standard parallels, normally established every 24 miles along the principal meridian.  On the standard parallels, there are offsets in the meridional lines and two sets of corners--standard corners (300 0001) for the lines to the north and closing corners for the lines from the south.  Township and section lines may be made closure lines to maintain rectangularity.  Measurement error, corrected on extension or resurvey, can result in double sets of corners and are shown on the map by offset lines.  The south and east boundaries are normally the governing lines of a survey; therefore, for digitizing purposes, corners at lines to the south and to the east are considered the closing corners.  Closing corners are also established where the lines of the rectangular system intersect or close on the boundaries of grants or reservations, on State boundaries, or on some other previously established survey that is irregular as to plan.  A closing corner is coded whenever a survey line closes on or crosses a boundary that delimits the public lands.  If the reservation boundary is coincident with a township or range line, the exterior township corners that are coincident with the reservation boundary are not closing corners and should not be attributed as closing corners.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000004

Meander corner.  The beds of navigable bodies of water are not public domain and are not subject to survey and disposal by the United States.  At every point where a section line intersects the banks of such a feature, a meander corner is established, and a metes and bounds traverse, called a meander line, is run to segregate the water area from the public lands.  Meander lines are not mapped.  Meander corners are shown only when recovered during field work; they are depicted as a double-weight (0.01 inch) "T", and are labeled "MC" as shown by symbols 523(A), 523.7(C) or 2502.10(D).  Unless the symbol and label are present, an unattributed node should be placed at the point where the section line is broken by a water body.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000005

Auxiliary meander corner.  When a lake of greater than 50 acres lies completely within a quarter section or an island too small to subdivide lies completely within a section, an auxiliary meander corner is established at any point on the shoreline and tied to the nearest regular corner.  A meander line is then run from the auxiliary meander corner.  Recovered auxiliary meander corners are shown with a monument symbol and labeled.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000006

Special meander corner.  When a lake of greater than 50 acres lies completely within a section, a special meander corner is established at an intersection of the center line of the section with the bank of the lake, and a meander line is run from the corner.  Special meander corners are also established at the intersections of surveyed subdivision of section lines and meander lines.  Recovered special meander corners are shown with a monument symbol and labeled.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000007

Witness corner.  A witness corner is established if the true corner cannot be marked in the usual manner because of obstructions or difficult terrain.  It is located on the section line within 10 chains (660 feet) or anywhere within 5 chains (330 feet) of the actual corner.  Normally, only one witness corner is established in each instance.  For example, witness corners are commonly established on secure ground when the true position of a meander corner falls at a point where the monument would be likely to be destroyed by the effects of tide, waves, or ice.  Witness corners are only mapped if they are recovered; they are depicted as a double weight (0.01 inch) "T" and labeled "WC" as shown in symbols 523(A), 523.7(C), or 2502.09(D).  If a witness corner is depicted that does not fall on a public land line, it is captured as a degenerate line feature (300 0302).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000008

Witness point.  This is a monumented station on a survey line marking an important location remote from and not related to a regular corner (for example, a road or stream crossing).  Recovered witness points are shown with horizontal coordinates as shown by symbols 216(A) or 512.99(C) and labeled "WP."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000009

Angle point.  This is a point in a survey marking a change in azimuth of an irregular boundary line.  Recovered angle points are sometimes shown with the identified (found) corner symbol as shown by symbols 506, 507 (A); 523.5, 523.6 (C); or 2502.07, 2502.08 (D) and labeled "AP".  Angle points that are not recovered are not captured as nodes, but rather are treated as inflection points of line features.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000010

Location monument (includes amended monument and mineral monument.)  Location monuments mark fixed reference points supplementing the regular public land survey.  There are three distinct occurrences of this feature:  Mineral monument - These monuments are established during surveys of the irregular boundaries of mining claims when no public land corners have been established in the vicinity.  When the public land surveys are subsequently extended to the area, the mineral monument is tied to a regular section corner.  Amended monument - Defective township exteriors that were not closed upon and from which subdivisional lines were not run are obliterated after a resurvey.  If, however, another survey was tied to a defective corner, that corner is retained as an amended monument.  Location monuments - These monuments are depicted as a filled triangle on the black plate as shown by symbols 227(A), 112.46(B), 512.106(C), or 2102.12(D) and are usually labeled with identifying letters and numbers.  In  most  cases  a  location  monument  does  not fall on a public land line and is captured as a degenerate line feature (300 0300).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000011

Reference monument.  This is an accessory placed near a corner that cannot be permanently marked, for example, the corner falls within a roadway and nearby bearing objects are not available.  It is shown by symbols 226(A) or 512.105(C).  Accessories may be searched for and mapped when corners are not found.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000012

Quarter-section corner.  This is a corner at the extremity of a quarter-section boundary, theoretically located halfway (40 chains) between section corners.  Normally, quarter-section corners are not searched for or plotted unless there is a bend in the line at the corner or the section corners on either side cannot be recovered.  This code is only used when the identified (found) corner symbol as shown by symbols 506(A), 523.5(C), or 2502.07(D) is shown.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000013

Tract corner.  A tract corner is an angle point, or change in azimuth, on a tract boundary.  In modern public land survey, the term tract is used to mean a parcel of land that lies in more than one section or cannot be identified in whole as part of a particular section.  Tract boundaries are not mapped unless they are needed to show the limits of the land net.  In this case, the extreme boundaries only are shown by the symbols 500(A), 523.10(C), or 2502.01(D).  It is not always possible to differentiate between tracts and grants based on the published map.  The grant corner code is only used when the identification of the feature as a tract corner is definite and obvious.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000014

Land grant or donation land claim corner.  A land grant or donation land claim (DLC) corner is an angle point, or change in azimuth, on a grant or DLC boundary.  In many States, there are irregular grant boundaries that were established prior to the original public land subdivisional surveys.  Donation land claims were established in Oregon and Washington prior to public land subdivisional surveys.  Grant and DLC boundaries are shown by symbols 500(A), 523.10(C), or 2502.01(D).  This code is used whenever a node is placed at an angle point on a grant or DLC boundary.  However, angle points on these boundaries are digitized as inflection points of linear features unless:  (1) a found land grant monument symbols 501(A), 523.11(C), or 2502.02(D) is shown, or (2) another surveyed line intersects the grant or DLC boundary at that point.  Where the public land lines close on or intersect grant or DLC boundaries, the closing corner code (300 0003) is used.  If the intersection is at an angle point on the grant or DLC boundary, the "Land grant or DLC corner" code is also assigned.  Nodes placed where grants intersect the neatline of the map or where grant lines are broken for features of higher order symbology, have no attributes.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000015

Arbitrary section corner.  This code is used when a node is placed in the approximate location of the true corner to effect closure of the land line network.  Joining to an arbitrary section corner is one of three methods of closing polygons to complete the definition of a coherent overlay.  Polygon closure is discussed in detail in section 3.12.5 (see code 300 0203).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000100

Indian lands.  Land granted to the native Indians is excluded from the public domain.  Tribal lands are shown on published maps with the reservation boundary shown by symbols 207(A), 123.6(B), 512.128(C), or 2107.05(D).  The reservation name is placed across the bounded area.  Boundaries of abandoned reservations that are limiting lines of subdivision surveys are shown on maps with the section line symbol and labeled "Old Indian Treaty Boundary" as shown by symbol 523.14(C).  When these lines do not limit the public lands, they are digitized only on the boundaries overlay and are coded as "Historical line."
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000101

Homestead entries.  Title to portions of the public domain was granted to individuals under the various homestead acts on the basis of residence, cultivation, and some improvement to the land over several years.  The use of this code is somewhat limited   because  homestead  entries   cannot  reliably  be  identified  on  published  maps.    This  code  is not used for tracts of land in Hawaii that are labeled as homesteads because Hawaii is not a public land state.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000102

Donation land claims.  Tracts of land (160, 320, or 640 acres) were allocated to settlers in the Oregon Territory who had resided on and cultivated the land for 4 years under the Donation Act of September 27, 1850; to settlers in Florida under the Act of August 4, 1842; and to settlers in New Mexico under the Act of July 22, 1854.  The boundaries of these areas are shown by symbols 500(A), 123.5(B), 523.10(C), or 2502.01(D) and the areas are usually numbered within a township.  Within the affected areas, polygons bounded by the grant line symbol are coded as donation land claims.  In addition, these areas are normally assigned the land grant identifier code (307 ----).  Angle points on the boundaries are coded as grant corners when appropriate.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000103

Land grants or civil colonies.  Grants established prior to the original subdivisional surveys are segregated from the public lands.  The boundaries of these irregular areas are shown by symbols 500(A), 123.5(B), 523.10(C), or 2502.01(D).  The names of named land grants, for example Spanish grants in California, are shown in black on the published maps.  The word "grant" is omitted unless the entire quadrangle falls within the grant.  Numbered or named grants include the land grant number code (307 ----).  See code 300 0106 for overlapping land grants.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000104

Private extension of public land survey.  The term "private" refers to any public land survey not performed by or contracted by the Bureau of Land Management.    Such  surveys  may  be  depicted  on  the published map by using dotted lines shown by symbols 508, 509 (A); 523.12, 523.13 (C); or 2503.01, 2503.02 (D).  They include, for example, Bureau of Indian Affairs surveys on Indian lands.  These areas are also assigned origin of survey, township, range, and section number parameters as appropriate.  They may also include an identifier of the type of land surveyed.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000105

Area of public and private survey overlap.  Private surveys may overlap the public land surveys.  Such areas are assigned this code.  They may also carry two sets of township, range, and (or) section numbers if the designations of the public and private surveys do not agree.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000106

Overlapping land grants.  Where land grants overlap because of survey error or disputed claims, this code is used.  The land grant code (300 0103) is not required in these cases.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000107

Military reservation.  This code is used for military or lighthouse reservations that limit the public lands.  The boundaries of these areas are shown on the map with the reservation boundary shown by symbols 207(A), 512.128(C), or 2107.03(D).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000108

Private survey.  This code is used only in PLSS states where private surveys are encountered.  This code does not include land grants, donation land claims, private extension of public land survey, area of public and private survey overlap, or other excluded areas now found in the DLG codes.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000109

Other reservation.  This code identifies other reservations (not military reservations) that limit the public lands and are included on the land plat and the graphic map.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000198

Water.  The areas of navigable streams and meanderable lakes are excluded from the public lands and should be assigned this attribute.  These areas are generally bounded by arbitrary closure lines because the actual meander lines are not mapped and land lines are broken at these bodies of water.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000199

Unsurveyed area.  This code is used when land lines are omitted from any area that is a part of the public domain.  It is also used for areas outside of the original public domain, that is, for the Thirteen Original States, Texas, Canada, and Mexico, when such areas are depicted on maps that partially cover public land States.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000203

Arbitrary closure line.  Arbitrary lines must occasionally be digitized to effect closure of all polygons of a PLSS file.  This most frequently occurs where land lines intersect navigable bodies of water because the actual meander lines are not mapped.  Closure lines may be digitized in one of the following ways: - as straight line segments joining existing nodes, - as approximate metes and bounds (distance and direction) traverses along the limits of another feature, or - as straight line extensions to an arbitrary section corner (300 0015).  In positioning arbitrary closure lines at water bodies, consider that meander lines are run in original surveys not as boundaries but to define the sinuosity of the feature, and as a means of ascertaining the quantity of land remaining after segregation of the water area.  They are run as a series of straight line segments that approximate the true margin of the feature.  Thus a major consideration in digitizing these lines is to avoid introducing excessive error into computations of land area.  It is also important to note that the position of bodies of water may change over time, but surveyed lines remain in their original locations.  Land lines are mapped as originally surveyed, even if the shorelines of meandered water bodies have changed.  Therefore, closure lines at water bodies should not be extended to or pulled back from the mapped shoreline where discrepancies exist.  In the past, land lines were broken at tract boundaries, but the tract limits themselves were not shown.  This most frequently occurred in the Rocky Mountain region.  In such cases, the arbitrary closure lines are digitized as straight line segments between nodes placed at the points where the land lines terminate.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000204

Base line.  This is a line extending east and west along a true parallel of latitude passing through the initial point.  It serves as the origin for the survey of meridional township boundaries.The base line of a survey is shown as a 0.010 inch solid line labeled in black as "base line" on 1:24,000-scale maps (with reference A symbols), or as a 0.010 inch solid line labeled in red as "Base Line" on 1:100,000-scale maps (reference B symbols), and on 1:24,000- or 1:25,000-scale maps (reference C symbols).  The use of this code is only required in conjunction with those surveys in Ohio and Indiana that do not have an initial point for the origin of both township and range numbering (see part 3.12.4.1, Origin of survey code).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000205

Claim line, grant line.  This code identifies non-PLSS lines dividing areas that are excluded from the PLSS.  It is used only on the lines that are completely within such excluded areas.  For example, this code would identify the dividing line between two contiguous donation land claims.  It would not be used on section lines surrounding the two.  This code is no longer used in DLG's but may appear in older DLG-3 files.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000299

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.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000300

Location monument.  These monuments are depicted as a filled triangle on the black plate as shown by symbols 227(A), 112.46(B), 512.106(C), or 2102.12(D) and are usually labeled with identifying letters and numbers.  This code is used for mapped location monuments shown by symbols 227(A), 512.106(C), or 2102.12(D) that do not fall on a section line.  If a location monument falls on a section line, it is collected as a node (300 0010).
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000301

Isolated found section corner.  Recovered section corners shown by symbols 506(A), 523.5(C), or 2502.07(D) may be shown on maps in areas where subdivision lines are omitted because of insufficient data.
USGS/NMD
United States Geological Survey/National Mapping Division
ENT
3000302

Witness corner (off surveyed line.)  A witness corner is established if the true corner cannot be marked in the usual manner because of obstructions or difficult terrain.  It is located on the section line within 10 chains (660 feet) or anywhere within 5 chains (330 feet) of the actual corner.  Normally, only one witness corner is established in each instance.  For example, witness corners are commonly established on secure ground when the true position of a meander corner falls at a point where the monument would be likely to be destroyed by the effects of tide, waves, or ice.  Witness corners are only mapped if they are recovered; they are depicted as a double weight (0.01 inch) "T" and labeled "WC" as shown in symbols 523(A), 523.7(C), or 2502.09(D).  This code is used for mapped witness corners shown by symbols 523(A), 523.7(C), or 2502.09(D) that have been placed off a surveyed line.  Witness corners on surveyed lines are captured as nodes (300 0007).
USGS/NMD
United States Geological Survey/National Mapping Division