USGS DIGITAL CARTOGRAPHIC DATA STANDARDS 

USGS Circular 895-A: Overview and USGS Activities 

B: Digital Elevation Models 

C: Digital Line Graphs from 1:24,000-Scale Maps 

D: Digital Line Graphs from 1:2,000,000-Scale Maps 

E: Land Use and Land Cover Digital Data 

F: Geographic Names Information System 

G: Digital Line Graph Attribute Coding Standards 

Questions regarding availability and ordering of US GeoData (all 

types of digital cartographic and geographic data produced and 

distributed by the u.s. Geological Survey) should be addressed to: 

User Services Section 

National Cartographic Information Center 

u.s. Geological survey 

507 National Center 

Reston, Virginia 22092 

Technical questions and comments should be addressed to: 

Chief, National Mapping Division 

u.s. Geological survey 

516 National Center 

Reston, Virginia 22092 

Any use of trade names and trademarks in this publication is for 

identification purposes only and does not constitute endorsement by the 

u.s. Geological Survey. 
DIGITAL LINE GRAPHS FROM 1:24,000-SCALE MAPS 

By William R. Allder and Atef A. Elassal 

USGS Digital Cartographic Data Standards 

Edited by Robert B. McEwen, Richard E. Witmer, and Benjamin s. Ramey 

Geological survey Circular 895-c 

1984 
United States Department of the Interior 

WILLIAM P. CLARK, Secretary 

Geological Survey 

Dallas L. Peck, Director 

Library of Con~re~Js C•ta.loging in Publication Data Ma1n entry Under tlt~e: 

USGS digital cartographic data standards. Digital line 

graphs from 1:24,000-scale maps. 

(u.s. Geological Survey circular 895-C) 

Bibliography: p. 

Supt. of Docs. no.: I 19.4/2:895-C 

1. Map scales. 2. Digital mapping--Standards. 

I. Geological Survey (U.S.) II. Title: U.S.G.S. 

digital cartographic data standards. Digital line graphs 

from 1:24,000-scale maps. III. Series: Geological 

Survey circular ; 895 -'C. 

GA118.U732 1983 526 83-600190 

Free on application to Distribution Branch, Text Products Section, 

U. S. Geological Survey, 604 South Pickett Street, Alexandria, VA 22304 
FOREWORD 

In recent years, the disciplines of cartography and geography have undergone a rapid and striking reorientation as the 

techniques for digital collection and manipulation of data have 

evolved from fledgling laboratory procedures into dominant and 

driving forces that now pervade the disciplines. Digital techniques have provided a variety of new and powerful capabilities 

to collect, manipulate, analyze, and display spatial data. 

However, this evolution also has introduced a number of new and 

complex problems. One of the most pressing problems, and one 

which is receiving particular attention at present, is the issue 

of digital cartographic data standards. 

The u.s. Geological survey (USGS) has been actively 

developing digital cartographic and geographic techniques for 

over a decade and has taken significant steps to develop and 

define in-house standards governing the various types of 

digital cartographic data that are being collected and archived 

in a national digital cartographic data base. The in-house 

standards are expressed in the form of specifications documents 

that were prepared to govern collection of the data and in the 

form of user guides that were prepared for distribution with 

the data. 

In an effort to fulfill lead agency requirements for 

promulgation of Federal standards in the earth sciences, the 

documents have been assembled with explanatory text into this 

USGS Circular consisting of separately bound chapters. This 

Circular describes some of the pertinent issues relating to 

digital cartographic data standards, documents the digital 

cartographic data standards currently in use within the USGS 

National Mapping Division, and details USGS efforts to define 

national digital cartographic data standards. 

Chapter A is an overview in which the major issues involved 

in developing digital cartographic data standards are discussed 

and the activities of the USGS related to digital cartographic 

data production and standards development are described in 

detail. succeeding chapters comprise the pertinent documents 

that establish USGS in-house standards for the various types of 

digital cartographic data currently produced by the National 

Mapping Division--that is, digital elevation data, digital 

planimetric data, digital land use and land cover data, and 

digital geographic names data. 

This compendium of relevant material is prepared to serve 

as a benchmark and to assist ongoing efforts to establish 

acceptable standards and conventions for both Federal agencies 

and the public. 

Dallas L. Peck 

Director, 

u.s. Geological survey 

Department of the Interior 

iii 

R. B. Southard 

Chief, 

National Mapping Division 

u.s. Geological survey 
PREFACE 

This Circular is the result of the efforts of numerous individuals who have contributed to the research, development, and 

preparation of various digital cartographic and geographic standards for the National Mapping Division of the u.s. Geological 

survey. The individuals named as chapter authors represent both 

the originators of the various concepts as well as the writers 

who expanded and clarified these ideas. Their contributions, 

either to the concepts or the writing, are of such magnitude as 

to warrant crediting as authors. 

Atef A. Elassal was largely responsible for the original 

data structures and computer file formats that are used for the 

digital line graphs and digital elevation models. The attribute 

coding scheme was first developed by members of the Digital 

Applications Team under the direction of Robert B. McEwen. The 

Geographic Names Information system was conceived and developed 

by Sam Stulberg and Roger L. Payne. The Geographic Information 

Retrieval and Analysis System was developed by Robin G. Fegeas, 

K. Eric Anderson, Stephen c. Guptill, Cheryl A. Hallam, and 

William B. Mitchell. The small-scale digital line graph data 

structure and attribute coding scheme was developed by Warren E. 

Schmidt and Michael A. Domaratz. 

The Circular was compiled in part from various user guides 

and technical instructions of the National Mapping Division. 

These documents were originally prepared by several individuals: 

credit is acknowledged to G. Michael Callahan, A. Joan szeide, 

William R. Allder, Vincent M. Caruso, Hugh w. Calkins, Donna 

Cedar-southworth, and Cheryl A. Hallam. The compilation of the 

various guides, instructions, and other material into the 

Circular format was performed with major assistance by Clark H. 

Cramer, Eloise R. Byrd, and Cynthia L. Cunningham. 

We acknowledge these substantial contributions that have led 

to this publi~ation. 

iv 
CONTENTS 

Foreword ••••••••••••••••••••••••••••••••••••••••••••••••••• 

Preface •••••••••••••••••••••••••••••••••••••••••••••••••••• Abstract ••••••••••••••••••••••••••••••••••••••••••••••••••• 

Introduction ••••••••••••••••••••••••••••••••••••••••••••••• 

Data content ••••••••••••••••••••••••••••••••••••••••••••••• 

Data structure ••••••••••••••••••••••••••••••••••••••••••••• 

Attribute codes •••••••••••••••••••••••••••••••••••••••••••• 

Major attribute codes •••••••••••••••••••••••••••••••••• 

Minor attribute codes •••••••••••••••••••••••••••••••••• 

Sample attribute codes ••••••••••••••••••••••••••••••••• 

Sample DLG-3 structure ••••••••••••••••••••••••••••••••••••• 

Graph theory in DLG data ••••••••••••••••••••••••••••••••••• 

Area case •••••••••••••••••••••••••••••••••••••••••••••• 

Network case ••••••••••••••••••••••••••••••••••••••••••• 

Distribution formats ••••••••••••••••••••••••••••••••••••••• 

Source materials ••••••••••••••••••••••••••••••••••••••••••• 

Cell size and file extent •••••••••••••••••••••••••••••••••• 

Coordinate systems ••••••••••••••••••••••••••••••••••••••••• standard distribution format 

Optional distribution format ••••••••••••••••••••••••••• 

Data validation •••••••••••••••••••••••••••••••••••••••••••• 

Appendix A. 

Appendix B. 

Appendix c. 

Appendix D. 

Appendix E. 

Appendix F. 

Appendix G. 

Appendix H. 

Appendix I. 

Figure 1. 

2. 

3. 

Standard DLG distribution format (record 

contents) •••••••••.•.•••.•••••...•.•...•.••• 

Optional DLG distribution format (record 

contents) ••••••••••••••••••••••••••••••••••• 

Map projection parameters ••••••••••••••••••••• 

DLG attribute codes ••••••••••••••••••••••••••• 

Coordinate conversion ••••••••••••••••••••••••• Sample DLG data file (standard distribution 

format) ••••••••••••••••••••••••••••••••••••• 

Sample DLG data file (optional distribution 

format) ••••••••••••••••••••••••••••••••••••• 

Quadrangles digitized using pre-1983 

hydrographic codes •••••••••••••••••••••••••• 

Pre-1983 hydrographic attribute codes ••••••••• 

ILLUSTRATIONS 

Map elements showing roads, railroads, buildings, 

streams, and lake and forest areas ............ Sample line graph ............................... Window from Dixie Mountain, Oregon, quadrangle 

published USGS 1:24,000-scale map ............. 

v 

Page 

iii 

iv 

1 

1 

1 

2 

3 

4 

5 

5 

6 

8 

8 

11 

13 

16 

16 

16 

16 

17 

17 

20 

31 

43 

45 

63 

64 

68 

71 

74 

Page 

4 

6 

9 
4. Window from area line graph of Public Land 

Survey System, Dixie Mountain, Oregon, 

Page 

quadrangle •••••••••••••••••••••••••••••••••••• 10 

5. Window from network line graph of roads and 

trails for the Fairdealing, Kentucky, 

quadrangle •••••••••••••••••••••••••••••••••••• 12 

6. Window from Fairdealing, Kentucky, quadrangle 

published USGS 1:24,000-scale map ••••••••••••• 13 

7. Location of origin of file reference 

coordinates ••••••••••••••••••••••••••••••••••• 17 

TABLES 

Page 

Table 1. Major codes used for DLG base categories •••••••• 5 

2. Digital description of sample level 3 

line graph •••••••••••••••••••••••••••••••••••• 7 

3. Selected sample of standard format DLG-3 records 

for Dixie Mountain, Oregon, Public Land Survey 

System • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 11 

4. Selected sample of standard format DLG-3 records 

for Fairdealing, Kentucky, roads and trails ••• 14 

vi 
USGS Digital Cartographic Data Standards 

DIGITAL LINE GRAPHS FROM 1:24,000-SCALE MAPS 

By William R. Allder and Atef A. Elassal 

Abstract 

The discipline of cartography is 

undergoing a number of profound changes 

that center on the emerging influence of 

digital manipulation and analysis of 

data for the preparation of cartographic 

materials and for use in geographic information systems. Operational requirements have led to the development by the 

USGS National Mapping Division of several 

documents that establish in-house digital 

cartographic standards. 

In an effort to fulfill lead agency 

requirements for promulgation of Federal 

standards in the earth sciences, the 

documents have been edited and assembled 

with explanatory text into a USGS 

Circular. This Circular describes some 

of the pertinent issues relative to 

digital cartographic data standards, 

documents the digital cartographic data 

standards currently in use within the 

USGS, and details the efforts of the USGS 

related to the definition of national 

digital cartographic data standards. It 

consists of several chapters; the first 

is a general overview, and each succeeding chapter is made up from documents 

that establish in-house standards for one 

of the various types of digital cartographic data currently produced. This 

chapter, 895-C, describes the data format 

and structure together with current 

attribute codes used for digitizing USGS 

1:24,000-scale maps. 

INTRODUCTION 

This document describes the digital 

line graphs (DLG's) prepared from the 

7.5-minute, and in some cases 15-minute, 

materials associated with the USGS Topographic Map Series. The series will 

eventually provide complete national 

coverage. The data are collected from 

7.5-minute source materials at 1:24,000 

or 1:25,000 scale where possible; when 

7.5-minute sources are not available, 15-

minute sources at 1:48,000 or 1:62,500 

scale are used. 

The digital data are useful for the 

production of cartographic products, such 

as base maps, and the data are structured 

to support the analytical functions of 

geographic information systems. A typical use of base category digital cartographic data is to combine them with 

other geographically referenced data, 

enabling various automated spatial 

analyses to be conducted. 

DATA CONTENT 

The DLG data files derived from the 

7.5- and 15-minute maps contain selected 

base categories of cartographic data in 

digital form; these data categories do 

not necessarily correspond to the traditional feature separates associated with 

graphic maps. one or more of the 

following categories may be included in 

current DLG files: 
• 

• 

Boundaries -- This category of data 

consists of (1) political boundaries 

that identify States, counties, 

cities, and other municipalities, and 

(2) administrative boundaries that 

identify areas such as national and 

State forests. Political and administrative boundaries are always 

collected as a single data set. 

Hydrography -- This category of data 

is currently being collected as 

combined hydrography consisting of 

all flowing water, standing water, 

and wetlands. 

Prior to 1983, hydrographic data were 

differentiated into two components: 

streams and water bodies. streams 

represent flowing water and were 

digitized as a network intended for 

hydrologic flow modeling. Streams 

included the banks of double-line 

rivers and centerline connectors 

placed through double-line rivers and 

lakes. Water bodies include standing 

water such as lakes and ponds. 

Wetlands and coastal hydrographic 

data were not collected. Appendix H 

contains a list of quadrangles for 

which hydrographic data were 

collected as streams and water 

bodies, .and Appendix I contains a 

list of the attribute codes used in 

these files. 

• Public Land Survey System (PLSS) --

This category of data describes the 

rectangular system of land surveys 

which is administered by the u.s. 

Bureau of Land Management. PLSS data 

are only collected for areas falling 

solely, or in part,-within the states 

which were formed from the public 

domain. The PLSS subdivides the 

public domain and represents property 

boundaries or referenc~s to property 

boundaries. These DLG data are not 

intended to be official or authoritative. They are presented as cartographic reference information. The 

only legal basis for determining 

land boundaries remains the original 

survey. 

2 

• Transportation -- This category of 

data includes major transportation 

systems differentiated into roads and 

trails, rai !roads, and pipeline and 

transmission lines. Data for all 

three are combined into a single data 

file, labeled transportation, for 

areas with sparse features. In areas 

with dense transportation features, 

the data are collected in three 

separate subcategories labeled: ( 1) 

roads and trails, (2) railroads, and 

(3) pipel~nes and transmission lines. 

DATA STRUCTURE 

The term digital line graph is employed by the USGS to describe a digital 

map data set in vector format in which 

the data are structured to one of the 

following levels. 

1. Level 1 This is the simplest 

structure which maintains the 

original (raw) data in a standardized 

format, coded to prescribed standards, and edited for normal input 

errors. The main purpose of this 

level is to meet three needs: (1) to 

provide a source of digital data 

quickly; (2) to provide data to users 

who can complete the structuring 

process; and (3) to provide data for 

plotting or display systems of low or 

moderate cartographic quality. 

2. Level 2 -- This structure is designed 

to support graphic display or plotting equipment of high cartographic 

quality. Level 2 DLG files contain 

extensive attribute codes that describe the graphic elements. 

3. Level 3 -- The third structure is 

used for fully topologically structured data files designed to be integrated into geographic information 

systems. All topological relationships have been defined for level 3 

DLG data. 

These three levels do not easily 

aggregate in an upward direction. Data 

collected under criteria and specifications for 1 evel 1 .or 1 evel 2 cannot 
always be enhanced to level 3. To 

achieve this level, it is often easier 

and more cost effective to recapture the 

data in level 3 form. However, the 

reverse process of extracting level 2 

from level 3 data, or level 1 from level 

2, is more easily accomplished. 

Current data collection from 7.5- and 

15-minute maps is almost exclusively 

directed toward producing level 3 DLG 

data refer red to as DLG-3. The DLG-3 

concept is based on graph theory in which 

a two-dimensional diagr~m is expressed as 

a set of nodes (point;s in space) and 

links (line segments connecting nodes) in 

a manner that explicitly expresses logical relationships. Applied to a map, 

this concept is used to encode the 

digital data with the spatial relationships between map elements which are 

obvious when the map is examined 

visually. The spatial relationships include such concepts as adjacency and 

connectivity between features on the map. 

The abstraction of the map data according 

to the rules of graph theory preserves 

the spatial relationships inherent in the 

map graphic and creates a logical and 

consistent data file structure for computer processing. A digital file of 

cartographic or geographic data that 

maintains the spatial relationships inherent in the map is called a topologically structured data file. A topologically structured data file can 

support simple graphic applications, such 

as plotting streams and roads for base 

maps, as well as more advanced applications, such as computations involving 

areas and lines and their spatial 

relationships. 

A DLG-3 file is composed of three 

separate, but related, elements: nodes, 

lines, and areas. Nodes define the location of the endpoints of every line, and 

a single node may mark the start or end 

of one or more lines. Intersections of 

lines are also marked by nodes and significant features on a line may also be 

marked by nodes. 

A line is an ordered set of points 

that describes the position and shape of 

a 1 inear feature on the map. Each 1 ine 

starts at a node and ends at a node and, 

thus, has both an explicit direction and 

a left-right connotation. Lines connect 

3 

to each other ·at nodes, and a line does 

not cross itself or any other 1 in e. A 

line may describe the boundary between 

two map features, such as counties, or 

may define a map feature by itself, such 

as a road. A special line, called a de~ 

generate line, is used to define features 

symbolized as points on a map. A degenerate line starts and ends at the same 

node, has zero length, and is totally enclosed inside one map area. 

An area is a portion of the map 

bounded by lines and all portions of the 

map must be assigned to some area. For 

each area defined in a DLG-3 data file, 

an arbitrary point is chosen to represent 

the characteristics of the area; the 

point is not required to be inside the 

area it represents. Every data file will 

have at least two areas defined: one 

representing the area covered by the file 

and the other representing the area outside the coverage of the file. Additional areas will be defined as necessary 

to subdivide the area covered by the 

file. 

ATTRIBUTE CODES 

In addition to locational and topological information, DLG data elements 

may have explicitly encoded attributes. 

Attribute codes, also called feature 

codes or classification attributes, are 

used to describe the map information 

represented by a node, area, or line. 

For example, the attribute code for an 

area might identify a park, lake, or 

county; the at tribute code for a line 

might identify a road, railroad, stream, 

shoreline, or boundary (fig. 1). The 

codes are based on the cartographic features symbolized on the USGS Topographic 

Map Series. This is the basic source 

material used to digitize and encode the 

data elements and therefore forms the 

overall classification strategy as contrasted to special purpose classifications of major features on the Earth 

which might be used for engineering or 

scientific applications. A listing of 

all the attribute codes currently assigned and used in the 7.5- and 15-minute 

DLG files is given in Appendix D, and a 

listing of attribute codes used to 
Figure 1.--Map elements showing roads, railroads, buildings, 

streams, and lake and forest areas. 

describe hydrographic features in DLG's 

digitized prior to 1983 is given in 

Appendix I. Detailed information on how 

to apply and interpret the attribute 

coding system with the hydrography and 

Public Land Survey System categories is 

given in Chapter G of this Circular. 

Each attribute code identifies the 

major category to which a data element 

belongs, as well as the specific nature 

of the element. Codes also may provide 

additional descriptive information. Most 

elements are uniquely described by a 

single attribute code. Others, however, 

may require two or more codes for a complete description. If multiple attributes are needed to describe an element, 

the order is not significant. Allowing 

for a variable number of attribute codes 

creates an open-ended structure to which 

information may be added at any time. It 

is not necessary for each element to have 

associated attributes; in general, attribute codes are not assigned to an element 

if the attributes can be derived based on 

relationships to adjacent elements. For 

example, a u.s. Public Land Survey section line is not assigned an attribute 

code because the 1 ine record carries a 

reference to the areas to the left and 

right that will be assigned attribute 

codes identifying the two different 

section numbers. The fact that the line 

is a section line is derivable. 

4 

A DLG attribute code is composed of 

two distinct numeric fields: a threedigit major code, which identifies the 

major category to which the element 

belongs, and a four-digit minor code, 

which specifically describes the element. 

In the digital file, the major and minor 

attributes are encoded in two integer 

fields of six digits, right justified 

with leading blanks (FORTRAN 2I6 format). 

In this document, major codes are presented as three digits, and minor codes 

are presented as four digits. Leading 

zeros are shown for clarity; for example: 

050 0412. 

MAJOR ATTRIBUTE CODES 

The first two digits of the major 

code uniquely identify the category to 

which the described element belongs. 

Table 1 lists the major codes and the 

categories they represent. 

The third digit of the major code is 

used to modify the minor code in two· 

ways: 

• If zero, the minor code represents a 

description or classification. of the 

element. 
Table I.--Major codes used for DLG 

base categories 

Major Code Base Category 

* 

** 

030* 

040* 

050* 

090 

100** 

110** 

130** 

300 

Streams 

water bodies 

Combined hydrography--streams, 

water bodies, and wetlands 

Boundaries 

Transportation systems--roads 

and trails 

Transportation systems--

railroads 

Transportation systems--pipelines 

and transmission lines 

u.s. Public Land Survey System 

Prior to 1983, hydrographic features were 

digitized as two separate base categories: 

(1) 030-Streams, and (2) 040-Water bodies. 

Hydrographic features are currently digitized as a single base category: 050-

Combined hydrography. See Appendix H for a 

list of quadrangles digitized using pre1983 hydrographic attribute codes. 

Transportation systems have been assigned 

more than one major code so that their 

components may be readily separated for 

analytical applications. Data for all 

three of the transportation categories are 

collected as a single data file for areas 

with sparse features. 

• If non-zero, the minor code which 

follows is a parameter requ1r1ng 

special interpretation according to 

instructions given in the codes for 

each category (see next section). 

MINOR ATTRIBUTE CODES 

The first digit of the minor code is 

normally zero. If non-zero, it is used 

as a modifier to provide additional information such as road access or railroad 

status. 

The remaining three digits are normally used to indicate the cartographic 

interpretation to be applied to specific 

elements. The type of element described 

5 

by a particular code usually can be 

determined from the range of value of the 

last three digits: 

001 - 099 

100 - 199 

200 - 299 

300 - 399 

400 - 499 

nodes 

areas 

lines 

points (degenerate lines) 

codes which may be 

applied to any element 

type (nodes, lines, 

areas, or points) 

601 - 699 = general descriptive codes 

The last three digits (and occasionally all four digits) also may be used as 

a parameter code. Parameters are used 

when a minor code can legitimately assume 

a range of values such as a water elevation or a highway route number. The 

meaning of a parameter code is indicated 

by the (non-zero) third digit of the 

major code. 

SAMPLE ATTRIBUTE CODES 

Three samples using the DLG attribute 

codes follow and should be interpreted 

with reference to Appendix D. 

Example A: 

050 0412 The major code 050 indicates 

the combined hydrography 

category. The minor code 

0412 identifies the feature 

as a perennial stream. 

Example B: 

100 1203 The major code 100 indicates 

the roads and trails category. 

Example C: 

The last three digits of the 

minor code identify the line 

feature as a primary route, 

hard surface (divided, width 

25' or more). The first digit 

of the minor code is non-zero 

and modifies the minor code 

by indicating limited access. 

306 0033 The major code 306 indicates 

an Origin of Survey code for 
y 

the u.s. Public Land Survey 

System category. Because the 

last digit of the major code 

is non-zero, the minor code 

is a parameter. The minor 

code 0033 indicates that the 

area element is referenced to 

the Willamette Meridian. 

28 L1 

N1 

27 

26 

25 

24 

EBA2 

23 

22 

21 .q20 ::.i 

19 

18 L4 

17 

16 z 

15 

14 

13 

12 

11 C') 

10 ::.i 

EBA3 

9 

8 

7 

6 

5 

4 

3 

2 

1 N12 

EB 

L3 

SAMPLE DLG-3 STRUCTURE 

A sample level 3 line graph ( DLG-3) 

and its corresponding digital records are 

given in figure 2 and table 2. (These 

examples are simplified representations 

of the concepts used in the DLG-3 structure; they are not actual data files.) 

N3 

N9 

• L12 L2 

EB A5 

co N6 ...J 

N5 

,.... 

...J 

N10 

N4 L10 

A1 

~~ Nl Ml.q-1 ~~col r-.1 ~~ ml ~~ ~1 ~~ ~~ ~~ ~~ ~~ ~~ ~~ ~~ ~~ Nl ~~ ~~ 

X 

Figure 2.--sample line graph. 

6 
Table 2.--Digital description of sample level 3 line graph (see fig. 2) 

Nodes lli.!!. 

Number X Coordinate Y Coordinate Number X coordinate Y Coordinate 

Nl 1 28 Al 0 0 

N2 13 14 A2 6 24 

N3 23 28 A3 3 10 

N4 13 1 A4 8 7 

NS 13 7 AS 18 14 

N6 22 10 

N7 6 5 

N8 10 4 

N9 11 24 

NlO 23 1 

Nll 1 17 

Nl2 1 1 

Lines 

Nodes Area Coordinates 

Number Starting: Ending Left Right (On!~ first and last shown) 

Ll 1 3 1 

L2 3 10 1 

L3 4 12 1 

L4 11 2 2 

LS 2 3 2 

L6 2 5 5 

L7 5 4 5 

L8 8 7 4 

L9 7 8 4 

LlO 4 10 5 

Lll 5 6 5 

Ll2 9 9 2 

Ll3 12 11 1 

Ll4 11 1 1 

The level 3 line graph shown is composed 

of 12 nodes, 5 areas, and 14 lines. The 

12 nodes are labeled Nl through Nl2. 

Each node is the starting or ending point 

for at least one line. Each element type 

is maintained as a separate 1 ist in the 

digital data, with pointers or linkages 

that express the topological relationships of connectivity and adjacency. The 

map can be completely described by 

considering the elements and their 

interrelationships. 

The map represented by the line graph 

is divided into five distinct areas 

2 

5 

3 

3 

5 

3 

3 

3 

3 

1 

5 

2 

3 

2 

7 

X(l) Y(28) X(23) Y(28) 

X(23) Y(28) X(23) Y(l) 

X(l3) Y(l) X(l) Y(l) 

X(l) Y(l7) ••• X(l3) Y(l4) 

X(l3) Y(l4) X(23) Y(28) 

X(l3) Y(l4) X (ll) Y(7) 

X(l3) Y(7) X(l3) Y(l) 

X(lO) Y(4) ••• X(6) Y(S) 

X(6) Y(S) ••• X(lO) Y(4) 

X(l3) Y(l) X(23) Y(l) 

X(l3) Y(l) ••• X(22) Y(lO) 

X(ll) Y(24) X(ll) Y(24) 

X(l) Y(l) X(l) Y(l7) 

X(l) Y(l7) X(l) Y(28) 

labeled Al through A5. Area Al represents all the area outside of the map 

border. There is one outside area for 

each DLG-3. It is always the first area 

encountered and has the at tribute code 

000 0000. In the example given in figure 

2, the portion of the map inside the 

border is divided into four areas, each 

bounded (closed) by lines. Area A2 is 

bounded by 1 ines Ll4, Ll, L4, and L5. 

Area A3 is bounded by lines L3, Ll3, L4, 

L6, L7, L8, and L9. Area A4· is bounded 

by lines L8 and L9. Area A5 is bounded 

by lines L5, L6, L7, and LlO and L2. 
As implemented in the standard DLG-3 

data structure, line elements contain the 

only explicit topological references. 

Each line contains pointers to its 

bounding nodes {starting and ending) and 

the areas that it bounds {left and right 

of the line). This format minimizes 

redundant linkages to achieve efficient 

data encoding and storage. 

The lines in figure 2 are labeled Ll 

through Ll4. The lines can be identified 

by their starting node number, ending 

node number, number of the area to the 

left of the direction of travel, number 

of the area to the right of the direction 

of travel, and string of coordinates 

describing the alignment of the line. In 

this example, only two coordinates are 

shown; however, in an actual file, an 

irregular line would have a variable 

number of coordinates. The direction of 

travel of the line is arbitrarily determined during the digitizing operation. 

In this example, Ll is encoded as proceeding clockwise around area A2. Thus 

line Ll starts at node Nl, ends at node 

N3, has area Al to the left of the 

direction of travel, and has area A2 to 

the right of the direction of travel. 

The coordinate string describing the 

alignment of the line will start with the 

same coordinate value as that of node Nl 

and will end with the same coordinate 

value as that of node N3. Because the 

area to the left of its direction of 

travel, Al, is different from the area to 

the right of its direction of travel, 

A2, the line is known to be a boundary 

between the two areas. 

Lines Lll and Ll2 are examples of 

lines which lie within one area. In 

this example, line Lll starts at node NS, 

ends at node N6, has area AS to the left 

of the direction of travel, and again has 

area AS to the right of the direction of 

travel. The coordinate string for the 

line will start with the same coordinate 

value as that of node NS and will end 

with the same coordinate value as that of 

node N6. Line Ll2 is an example of a 

degenerate line. The line starts at node 

N9, ends at node N9, and has area A2 as 

both the area to the left and right of 

the direction of travel. There are only 

two coordinates in the string defining 

the alignment of the line: both points 

8 

have the ·same coordinate value as node 

N9; thus, the two points are the same and 

the line has zero length. 

The line graph concept allows all of 

the points on the map to be described as 

a member of a line graph element {node, 

area, or 1 ine) with minimal redundancy. 

The relationships between the various 

elements are indicated by the structure. 

GRAPH THEORY IN DLG DATA 

There are two ways to implement the 

line graph concept in DLG files: the 

area case and the network case. These 

cases are differentiated by the nature 

of the information contained in the 

categories. 

AREA CASE 

Area 1 ine graphs are used to represent areal features such as political 

entities or water bodies in digital form. 

Area line graphs cor respond directly to 

the general line graph case in that each 

closed area on the map is represented by 

a distinct area element. Data categories 

that are collected as area line graphs 

include: 

• Boundaries, 

• Combined Hydrography, and 

• Public Land Survey System. 

Line elements for boundaries and the 

Public Land Survey System are not 

normally assigned attributes. The characteristics of lines in these categories 

can be derived by examining the attributes of the area elements on each side 

of the line. 

Figure 3 shows a window taken from 

the Dixie Mountain, Oregon, 7.S-minute 

quadrangle. Figure 4 shows the area 

1 ine graph encoded for the Public Land 

survey System of the same area. The 

nodes, areas, and lines are labeled. 

Table 3 contains some of the digital 

data records extracted from the node, 

area, and line lists which describe this 

portion of the graph. (Note: Descriptions of DLG-3 formats are contained in 
Figure 3.--Window from Dixie Mountain, Oregon, quadrangle 

published USGS 1:24,000-scale map. 

Appendixes A and B, and a list of 

attribute codes is contained in Appendix 

D.) 

In the Dixie Mountain example, each 

node and area element is described by 

two logical records: (1) a type D.l 

record that describes the element, and 

(2) a type F record that lists the attribute codes associated with the element. 

The first record (type D.l) for each node 

and area element contains the following 

fields: 

1. Type of record indicator (Nor A). 

2. Internal sequence identification 

number. 

3. x-coordinate of node or representative area point. 

4. y-coordinate of node or representative area point. 

s. Number of attribute codes that 

describe the element. 

9 

6. Number of pairs of characters 

in the text string that 

describes the element. 

The second record (type F) for each node 

and area element contains n attribute 

codes (expressed as major and minor code 

pairs), where n is the number specified 

in field 5 of the first (type D.l) 

record. 

Each line element in the Dixie 

Mountain example (except for line number 

140), is also described by two logical 

records: (1) a type D.2 line description 

record, and (2) a type E record that 

lists the x,y coordinate pairs that 

define the shape of the 1 ine. Line 140 

is described by a type F (attribute code) 

record in addition to the type D. 2 and 

type E records. The first record (type 

D. 2) for each 1 ine element contains the 

following fields: 
1. Type of record indicator (L). 

2. Internal sequence identification 

number. 

3. Internal sequence number of 

starting node. 

4. Internal sequence number of ending 

node. 

5. Internal sequence number of the 

area to the left of the line. 

6. Internal sequence number of the 

area to the right of the line. 

7. Number of x,y coordinate pairs 

that locate the line on the map. 

8. Number of attribute codes that 

describe the line. 

9. Number of pairs of characters in 

the text string that describes the 

line. 

The second logical record (type F) for 

each 1 ine element contains n coordinate 

pairs, where n is the number specified in 

field 7 of the first (type D.2) record. 

Area 22 Area 21 

In the Dixie Mountain example, all lines 

are straight and are, therefore, defined 

by only two coordinate pairs that are 

identical to the coordinates of the 

starting and ending nodes. 

The lines in the Dixie Mountain 

example (exc·ept for line number 140) do 

not have type F (attribute code) records 

because the at tributes of each line can 

be derived by noting the attributes of 

the left and right areas. For example, 

line number 63 is a township extremity 

line, symbolized on the published map as 

a double-weight line. This attribute of 

line 63 is not explicitly coded in the 

digital file but can be derived by noting 

that the township numbers of the areas to 

the left (area 28, 302 0003, Township 3 

North) and to the right (area 40, 302 

0002, Township 2 North) of the line are 

different. 

The explicit attribute record attached 

to line number 140 contains an attribute 

Area 20 

Line 69 

Node 88 Node 61 

r 

Section 34 :r 

(I) 

Township 3 North 

Range 2 West 

Willamette Meridian 

0 

Area 27 :! + Node 45 (I) 

c: 

:.::i 

Area 28 

Ea XY=(2679, 2053) Area 29 

c: 

::I 

(I) 

..... 

1\) 

Node 60 Line 63 Node 85 

Area 41 Area 40 Area 39 

Section 3 

Township 2 North 

Range 2 West 

Willamette Meridian 

Figure 4.--Window from area line graph for Public Land Survey System, 

Dixie Mountain, Oregon, quadrangle. 

10 
Table 3 .--Selected samEle of standard code (309 0009) that indicates coinformat DLG-3 records for Dixie cidence with a boundary, in this case the 

Mountain, Oregon, PLSS political boundary dividing Multnomah 

and Washington counties. The corresponding line in the boundaries file will 

N 45 3839 2202 be coded as coincident with Public Land 

300 14 3 00 40 Survey System ( 090 00 30) • This coding 

is intended to facilitate the integration N 60 12 41 943 of different categories of DLG data. 

300 300 40 The topological pointers contained in 

the DLG-3 line elements enable a user to N 61 3829 3527 manipulate the data based on the spatial 300 300 40 relationships. For example, many appli85 3851 883 cations require areal data to be ex300 pressed as closed strings of x,y coordinate pairs. The following procedure N 88 1215 3552 could be used to create a perimeter 

300 string of the section referenced in 

A 20 5092 4780 figure 4 as area 28. Area 28 has four 

attributes: Township 3 North (302 0003), 306 33 302 305 301 26 Range 2 West (305 000 2), Section 34 

A 21 2372 4 731 (301 0034), Willamette Meridian (306 

306 33 302 305 301 27 0033). 

A 22 -166 4 756 1. Identify the cor responding area 

306 33 302 305 301 28 element (area 28) in the data file 

A 27 -71 2265 by comparison with the attribute 

code lists. 306 33 302 305 301 33 2. Identify all line elements which 

A 28 2679 2053 bound area 28 by examining the 

306 33 302 305 301 34 line records for their area left 

and area right topological A 29 5024 2067 pointers. (Lines 63, 69, 111, 306 33 302 305 301 35 112, 140). 

A 39 5248 -620 3. Extract the x,y coordinates for 

the first line encountered (line 306 33 302 305 301 6 3) • Line 63 ends at node 85, so A 40 2606 -596 find another line which begins or 

306 33 302 305 301 ends at node 85. Line 112 ends at 

node 85, so its coordinates must A 41 80 -577 be extracted in the reverse of the 306 33 302 305 301 order in which they are stored. 

L 63 60 85 28 40 Now search at node 45, the beginning node of line 112 and proceed 1241 943 3851 883 as described above until the lines 69 61 88 28 21 in question are exhausted and the 

3829 3527 1215 3522 beginning node {node 60) is 

reached. {Note: This simplified L 111 61 45 29 28 procedure will not suffice for 3829 3527 3839 2202 more complex graphs which include, 

L 112 45 85 29 28 for example, island polygons.) 

3839 2202 3851 883 

L 140 88 60 28 27 NETWORK CASE 

1215 3552 1241 943 

Network line graphs are used to repre- 309 sent linear features such as roads or 

11 
streams in digital form. The network 

case differs from the area case in that, 

irrespective of the number of closed 

areas forming the graph, only two area 

elements are encoded: (1) the area outside the graph, termed the outside area; 

and (2) the area within the graph, termed 

the background area. All lines except 

the graph boundary are considered to be 

contained within the background area. 

The major topological relationship 

expressed by network data is that of 

connectivity. Data encoded in network 

line graph form are suitable for various 

forms of network analysis, such as 

minimum path computations. Data categories that are collected as network 

line graphs include: 

• Roads and trails, 

• Railroads, and 

• Pipelines and transmission lines. 

Figure 5 shows a window taken astride 

the western edge of the network line 

graph of roads and trails for the 

Fairdealing, Kentucky, 7.5-minute quadrangle. The window was placed astride 

the edge of the quadrangle to demonstrate 

the methodology used to encode data at 

the map neatline. Although the intersecting lines of the road network divide 

the graph into a number of areas, only 

two area elements are encoded, the background area and the outside area. Figure 

6 shows the same area on the published 

map, and table 4 lists some of the 

digital data records for this portion of 

the graph. 

Note that all line segments within the 

graph boundary are, by definition, contained in the background area. Area 2 is 

identified as being to the left and to 

the right of each 1 ine. Only the three 

lines which form part of the graph boundary, or map neatline (lines 644, 645, and 

Figure 5.--Window from network line graph of roads and trails 

for the Fairdealing, Kentucky, quadrangle. 

12 
Figure 6.--Window from Fairdealing, Kentucky, quadrangle 

published USGS 1:24,000-scale map. 

646), have distinct left and right area 

identifiers: they are bounded on one side 

by the outside area and on the other by 

the background area. 

Each node and area record is described 

by type D.l (description) and type F 

(at tribute code) logical records as was 

the case in the Dixie Mountain (area 

case) example. Note that area 2, which 

represents the background area, carries 

no attribute record. This is always the 

case with the background area in a network line graph. 

Each line segment in the Fairdealing 

example is described by type D.2 (line 

description), type E (coordinate list), 

and type F (attribute code) logical 

records as appropriate. The line segments that represent the roads and trails 

in this file are not straight (except for 

line 540) and are, therefore, described 

by more than two coordinate pairs. Line 

number 282, for example, begins at node 

356, ends at node 221, and is described 

by 14 pairs of coordinates. 

13 

Preservation of the topological relationship of connectivity is illustrated 

by the four line segments (lines 538, 

539, 540, and 541) that are all part of 

a single State road. Each line carries 

two attribute codes: 

100 0206 -

104 1364 -

secondary route, hard 

surface, unrestricted 

access, and 

State route 1364 

These segments can be joined at nodes 

to form a coherent description of route 

1364. 

DISTRIBUTION FORMATS 

The 7. 5- and 15-minute DLG data are 

available in two distribution formats: 

(1) standard and (2) optional. 
Table 4.--Selected sample of standard format DLG-3 records for 

Fairdealing, Kentucky, roads and trails 

(Leading zeros are not used in this table, and each 144-character record 

is shown as two consecutive 72-character lines.) 

N 221 -8784 -2449 0 

100 

N 222 -8509 -2211 1 0 

100 51 

N 223 -7658 -3666 1 0 

100 1 

N 224 -7080 -3862 1 0 

100 51 

N 3 55 -9148 -2667 1 0 

100 50 

N 356 -8008 -2328 0 

100 1 

N 360 -9147 -3161 1 0 

100 50 

N 361 -7641 -3733 1 0 

100 1 

A 1 -9525 -1872 1 0 

0 0 

A 2 447 268 0 0 

L 176 222 221 2 2 16 1 0 

-8509 -2211 -8525 -2228 -8548 -2243 -8547 -2245 -8624 -2236 -8660 -2222 

-8678 -2212 -8700 -2215 -8719 -2236 -8715 -2268 -8684 -2288 -8672 -2311 

-8683 -2343 -8708 -2373 -8763 -2423 -8784 -2449 

100 208 

L 177 224 223 2 2 8 1 0 

-7080 -3862 -7129 -3885 -7160 -3885 -7271 -3832 -7440 -3721 -7526 -3680 

-7595 -3661 -7658 -3666 

100 208 

L 281 355 221 2 2 8 1 0 

-9148 -2667 -9128 -2646 -9056 -2598 -9005 -2556 -8957 -2519 -8829 -2455 

-8805 -2448 -8784 -2449 

100 207 

L 282 356 221 2 2 14 1 0 

-8008 -2328 -8071 -2367 -8124 -2391 -8199 -2442 -8246 -2466 -8386 -2513 

-8497 -2553 -8555 -2566 -8620 -2589 -8647 -2588 -8667 -2574 -8727 -2497 

-8758 -2461 -8784 -2449 

100 207 

14 
Table 4.--Selected sample of standard format DLG-3 records for 

Fairdealing, Kentucky, roads and trails--continued 

L 283 357 356 2 2 36 1 0 

-5363 -966 -5377 -974 -5449 -1045 -5510 -1099 -5711 -1239 -5773 -1279 

-5921 -1356 -6043 -1390 -6089 -1411 -6130 -1440 -6168 -1484 -6199 -1527 

-6326 -1651 -6380 -1706 -6467 -1729 -6541 -1757 -6615 -1790 -6674 -1829 

-6781 -1874 -6843 -1895 -6940 -1908 -6987 -1925 -7036 -1935 -7070 -1956 

-7100 -1989 -7126 -2075 -7308 -2259 -7434 -2282 -7501 -2302 -7574 -2302 

-7741 -2284 -7883 -2264 -7912 -2266 -7947 -2283 -7979 -2310 -8008 -2328 

100 207 

L 287 361 360 2 2 20 1 0 

-7641 -3733 -7690 -3725 -7722 -3712 -7855 -3634 -8010 -3530 -8081 -3508 

-8130 -3487 -8262 -3466 -8353 -3441 -8433 -3428 -8465 -3414 -8499 -3391 

-8585 -3323 -8636 -3302 -8708 -3238 -8756 -3215 -8831 -3200 -8894 -3182 

-8941 -3164 -9147 -3161 

100 207 

L 538 213 356 2 2 32 2 0 

-7048 815 -7123 645 -7193 524 -7303 264 -7379 112 -7424 7 

-7450 -67 -7479 -127 -7521 -268 -7556 -434 -7591 -613 -7609 -739 

-7634 -846 -7659 -923 -7709 -1000 -7763 -1066 -7825 -1102 -7873 -1140 

-7933 -1194 -8001 -1271 -8064 -1349 -8118 -1426 -8151 -1526 -8166 -1606 

-8174 -1700 -8170 -1809 -8159 -1880 -8131 -1961 -8103 -2025 -8058 -2101 

-8038 -2156 -8008 -2328 

100 206 104 1364 

L 539 356 223 2 2 15 2 0 

-8008 -2328 -8008 -2373 -8018 -2428 -8018 -2593 -8015 -2651 -8007 -2685 

-7921 -2808 -7885 -2852 -7864 -2885 -7849 -2901 -7819 -2953 -7799 -3010 

-7776 -3095 -7720 -3396 -7658 -3666 

100 206 104 1364 

L 540 223 361 2 2 2 2 0 

-7658 -3666 -7641 -3733 

100 206 104 1364 

L 541 361 295 2 2 14 2 0 

-7641 -3733 -7628 -3821 -7620 -3930 -7622 -3997 -7639 -4061 -7702 -4251 

-7751 -4334 -7766 -4392 -7774 -4448 -7773 -4501 -7761 -4557 -7699 -4646 

-7681 -4665 -7647 -4716 

100 206 104 1364 

L 644 528 360 1 2 2 0 0 

-9151 -4962 -9147 -3161 

L 645 360 355 2 2 0 0 

-9147 -3161 -9148 -2667 

L 646 355 566 1 2 2 0 0 

-9148 -2667 -9146 617 

15 
The standard distribution format is a 

direct character representation of the 

binary archival DLG and, as such, 

reflects design decisions intended to 

minimize storage requirements. For 

example, explicit topological linkages 

are contained only in the line elements. 

The optional distribution format was 

designed strictly for data interchange. 

These files are typically larger than 

those in the standard format but, for 

certain applications, can simplify 

processing requiremen.ts. For example, 

because topological linkages are 

explicitly encoded for all 1 ine, node, 

and area elements, a polygon data structure can be easily created. 

The characteristics of the standard 

and optional DLG formats are summarized 

below: 

Character set 

Logical record 

length 

Physical record 

length (blocksize) 

Coordinate system 

Topological 

linkages 

8-bit ASCII 

144 bytes 

variable in 

multiples of 

144 bytes 

internal file 

contained only 

in line elements 

8-bit ASCII 

80 bytes 

variable in 

multiples of 

80 bytes 

ground 

planimetric 

(usually UTM l 

contained in 

node, area, and 

line elements 

These formats are described in detail 

in Appendixes A and B. 

SOURCE MATERIALS 

The DLG data files described in this 

document are derived from USGS topographic maps published as 7.5-minute 

quadrangles at 1:24,000 or 1:25,000 

scale. Where 7.5-minute coverage is not 

available, the following sources are 

used, in order of preference: 

1. Advance manuscripts for 7.5-minute 

maps, 

2. Archival compilation materials for 

15-minute quadrangles, if available at a larger scale than the 

published map, such as 1:48,000 

scale, or 

16 

3. Published 15-minute quadrangles at 

1:62,500 scale 

The scale of the source materials used 

to generate a DLG is contained in the 

file header. The scale is also reflected 

in the resolution field, which states the 

ground length in meters of the smallest 

data collection unit (0.001 inch) for 

each scale. 

Source scale 

1:24,000 

1:25,000 

1:48,000 

1:62,500 

Resolution 

0.61 meter 

0.63 meter 

1. 22 meters 

1.58 meters 

CELL SIZE AND FILE EXTENT 

The DLG' s are stored and distributed 

in standard cells of 7.5 minutes of latitude by 7 .5-minutes of longitude. Data 

collected from 15-minute quadrangles are 

partitioned into four 7.5-minute units. 

Non-standard cells are collected in 

coastal areas where map format is sometimes extended to conform to the shoreline. Such cells are readily identified 

by examining the geographic coordinate 

limits contained in the file header. 

COORDINATE SYSTEMS 

The positional descriptions for DLG 

data elements are expressed in one of two 

coordinate systems, dependent upon the 

distribution format selected. These are 

described as follows as the standard 

distribution format and the optional 

distribution format. 

STANDARD DISTRIBUTION FORMAT 

The DLG data in the standard distribution format are encoded using an internal 

file coordinate system to minimize 

storage requirements. The characteristics of this system are as follows: 

1. The coordinate system is 

Cartesian. 

2. The origin (x=O, y=O) is either: 
a. To the left and below the 

lower left corner of the cell 

or 

b. At the center of the cell 

(fig. 7). 

3. The x-axis of the coordinate 

system is parallel to a straight 

line connecting the southwest and 

southeast corners of the cell, 

that is, the southwest and southeast corners of the cell have 

identical y coordinates in the 

internal file coordinate system. 

4. One unit is equal to 0.001-inch at 

map scale. 

5. The coordinate domain is limited 

to the range -32767 to +32767. 

The file header contains the parameters of an transformation which can be 

used to convert the internal file coordinates to the ground planimetric 

(usually UTM) coordinate system. An 

example of this transformation is given 

in Appendix E. 

OPTIONAL DISTRIBUTION FORMAT 

The DLG data in the optional 

distribution format are expressed in the 

units of the ground coordinate system 

(usually meters in the UTM coordinate 

system). 

DATA VALIDATION 

The DLG data do not currently carry 

quantified map accuracy statements. The 

following procedures, however, are used 

to validate the data files before they 

are released for distribution: 

File fidelity and completeness -- The 

data are manually digitized using 

equipment with a resolution of 0.001 

inch and an absolute accuracy of from 

0.003 to 0.005 inch. The positional 

accuracy of the data and completeness 

of the file are checked by visually 

comparing proof plots with the 

original stable base source material. 

These proof plots are generated using 

automated drafting machines with a 

resolution of 0.001 inch and an 

absolute accuracy of from 0.003 to 

0.005 inch. 

Attribute accuracy DLG attribute 

codes are checked by software against 

a table of valid codes to ensure that 

each attribute in a file is valid for 

the category and element type to which 

it is assigned. Validating the codes 

for correct application is currently a 

manual process involving the cor relation of formatted listings with proof 

plots. 

Topological fidelity The topological structure of each DLG file is 

", // 

Q) 

u 

a. 

ctl 

E 

"E 

ctl 

"0 

c: 

ctl 

U5 

" / " / " / " / " / " / 

~Center origin 

// " 

/ " 

/ " 

/ " 

/ " 

/ " 

// ', ffi Lower left corner origin 

Figure 7.--Location of origin of file reference coordinates. 

17 
fully validated by software. There 

are no extraneous intersections; that 

is, a 1 ine does not join or cross 

another 1 ine, or itself, except at a 

node. No line extends through a node. 

Polygon (area) adjacency is also 

validated; that is, area left and 

right topological attributes of lines 

are consistent throughout the file. 

18 

Validation of DLG data is performed 

for each category within a file. The 

data are not digitally edge matched to 

adjacent cells. There is currently no 

attempt, other than the coding of coincident features, to provide fully integrated data layers (usually termed 

vertical integration). 
APPENDIXES 
APPENDIX A.--Standard DLG Distribution Format 

(Record Contents) 

In the standard DLG distribution format, the topological linkages are 

contained only in the line elements. The files are physically comprised 

of standard 8-bi t ASCII characters organized into fixed-length logical 

records of 144 characters. Nine distinct record types are defined. 

Logical 

Record 

Type 

A 

B 

c 

D.l 

D.2 

E 

F 

G 

H 

Content 

Header record containing DLG 

identification information 

Header record containing projection 

information and registration points 

Header record identifying data categories 

contained in this DLG and indicating the 

number of nodes, areas, and lines in each 

category. 

A node or an area record 

A line record 

Record containing x,y coordinate string 

Record containing attribute codes 

Record containing text string (text record is 

rarely used) 

Accuracy estimate (record H is not currently used for any 

DLG file) 

20 
APPENDIX A.--standard DLG Distribution Format 

(Record Contents)--continued 

The actual sequence of records in a standard distribution DLG file is as 

follows: 

1. 

2. 

Header records 

Type A (one record) 

Type B (one record) 

Type c (one record) 

Data records 

Node records 

Node description (D.l) 

Attribute codes (F) 

Text string (G) 

Area records 

Area description (D.l) 

Attribute codes (F) 

Text string (G) 

Line records 

Line description (D.2) 

x,y coordinates (E) 

Attribute codes (F) 

Text string (G) 

3. Accuracy estimate 

l Repeated 

for each 

node within a 

data category 

l Repeated 

for each 

area within a 

data category 

l Repeated 

for each 

line within a 

data category 

Type H (one record) (not currently used) 

Repeated 

for each 

data category 

Descriptions of the contents of records A-F are contained in the following 

tables. The tables also reflect the relationship between these record 

types and 144-byte logical records. 

21 
IV 

IV 

Record 

Number 

A.l 

A.l 

A.l 

A. 2 

A.2 

A.2 

A.2 

APPENDIX A.--standard DLG Distribution Format (Record Contents)--continued 

Data 

Element 

1 

2 

3 

1 

2 

3 

4 

[Integer fields with a value of zero will have leading zeros suppressed. 

For example, an I6 field would be "bbbbbO". (b =blank)] 

[Any field with the format of D24.15 which has a value of zero will be 

represented as "bbbO.Obbbbbbbbbbbbbbbbbb". (b=blank)] 

Contents 

Name of digital 

cartographic unit 

Filler 

Date of original 

source materials 

Filler 

Scale of original 

source material 

Filler 

DLG level code 

Code defining 

ground planimetric 

reference system 

Code defining zone 

in ground planimetric reference 

system 

Map projection 

parameters 

Filler 

Logical Record Type A 

Type 

(Fortran Notation) Format 

ALPHA MO 

ALPHA AlO 

INTEGER*4 I8 

INTEGER*2 I6 

INTEGER*2 I6 

INTEGER*2 I6 

REAL*8 5024.15 

Starting Ending 

Byte Byte 

1 40 

41 41 

42 51 

52 52 

53 60 

61 144 

1 6 

7 12 

13 18 

19 138 

139 144 

Comment 

The name of the map will be 

used when practical. 

1 space 

Year of original source 

material, followed by latest 

photorevision date if 

applicable, for example, 

1956, 1965. 

1 space 

Scale denominator of source 

material, for example, 

62500. 

84 spaces 

Code=3, DLG-3 

Code=!, Universal Transverse 

Mercator (UTM) 

Codes for UTM coordinate 

zones are given in 

Appendix c. 

This field contains the 

first 5 of 15 map projection 

parameters. Parameters 

for the UTM projection are 

given in Appendix c. 

6 spaces 
APPENDIX A.--Standard DLG Distribution Format (Record Contents)--continued 

Logical Record Type A--continued 

Record Data Type Starting Ending 

Number Element Contents (Fortran Notation) Format B~te Byte Comment 

A.3 1 Map projection REAL*8 6024.15 1 144 This record contains 

parameters projection parameters 6 

thru 11. Parameters for the 

UTM projection are given 

in Appendix c. 

A.4 1 Map projection REAL* 8 4024.15 1 96 This field contains the 

parameters last 4 projection 

parameters. Parameters for 

the UTM projection are given 

in Appendix c. 

N 

w A.4 2 Code defining units of INTEGER*2 I6 97 102 Code=2, meters 

measure for ground 

planimetrrc coordinates 

throughout the file 

A.4 3 Resolution REAL*8 024.15 103 126 The true ground distance 

corresponding to one unit 

(0.001 inch at map scale) in 

the file internal reference 

system. This value 

corresponds to the scale of 

the source document as 

follows: 

Scale Resolution 

1:24,000 0.61 M 

1:25,000 0.63 M 

1:48,000 1.22 M 

1:62,500 1.58 M 

A.4 4 Accuracy code of INTEGER*2 I6 127 132 Code=O, unknown accuracy 

planimetric data 
IV 

.1;>-

Record 

Number 

A.4 

A.5 

A.6 

Data 

Element 

5 

1 

APPENDIX A.--standard DLG Distribution Format (Record Contents)--continued 

Logical Record Type A--continued 

Type 

Contents (Fortran Notation) Format 

Number (n) of sides 

in the polygon which 

defines the coverage 

of the cell 

Filler 

A (4,2) array containing geographic 

coordinates of the 

polygon which 

contains the domain 

of the OLG file 

Filler 

INTEGER*2 

REAL*8 

I6 

3(2024.15) 

2024.15 

Starting Ending 

Byte Byte 

133 

139 

1 

1 

49 

138 

144 

144 

48 

144 

Comment 

n=4 

6 spaces 

The four-sided polygon will 

usually coincide with an 

area defined by one of the 

standard map formats of 

the National Mapping 

Program. coordinates 

are in geographic 

longitude and latitude 

in units of degrees and 

decimal degrees and are 

espressed in the order=SW, 

NW, NE, SE. 

96 spaces 
IV 

L71 

Record 

Number 

B.l 

B.l 

B.2 

Data 

Element 

1 

2 

1 

APPENDIX A.--standard DLG Distribution Format (Record Contents)--continued 

Logical Record Type B 

Type 

Contents (Fortran Notation) Format 

Parameters (Al, A2, 

A3, A4) of fileto-ground projection 

transformation~ the 

explicit form of the 

transformation is: 

X=Alx+A2y+A3 

Y=Aly-A2x+A4 

where: 

x,y are coordinates in 

file internal reference 

system X,Y are coordinates in map projection reference system 

Number (m) of registration points 

Filler 

A (4,3) array containing identifications 

and coordinates of 

registration points. 

Coordinates are 

expressed in the file 

internal reference 

system 

Filler 

REAL*8 

INTEGER*2 

ALPHA/ 

INTEGER*2 

4024.15 

!6 

4 (A2 1 2!6) 

Starting Ending 

Byte Byte 

1 96 

97 102 

103 144 

1 56 

57 144 

Comment 

X,Y coordinates resulting 

from this transformation 

will be in ground meters in 

UTM zone defined by data 

element 3 of record A.2. 

m=4 

42 spaces 

The corners of a four-sided 

polygon are used as 

registration points. The 

identification sequence is 

SW, NW, NE, SE. The array 

is stored by row. 

Coordinates in the file 

internal reference system 

are expressed in units of 

thousandths of an inch and 

fall in the range -32768 to 

+32767. These coordinates 

correspond to the geographic 

coordinates contained in 

records A.5 and A.6. 

88 spaces 
N 

0"1 

Record 

Number 

C.l 

C.21 

to C.N 

Data 

Element 

1 

1 

APPENDIX A.--standard DLG Distribution Format (Record Contents)--continued 

Logical Record Type c 

Type Starting Ending 

Contents (Fortran Notation) Format Byte Byte 

Number (q) of 

categories 

in the DLG file 

Filler 

A (q,7) array containing category names as 

well as maximum and 

actual number of node, 

area, and line elements 

in each category 

Filler 

INTEGER*4 

ALPHA/ 

INTEGER*2 

I6 1 

7 

q (A20, 6I6) 1 

(57 

6 

144 

56 

112) 

Comment 

1~~32. Up to 32 categories 

can be represented in a 

given file. The value will 

usually be between 1 and 5. 

138 spaces 

This array is stored by 

row. The first element is 

the category name consisting 

of 20 alphanumeric characters the first four of 

which are unique. Columns 2 

and 3 of the array contain 

maximum and actual number of 

nodes in the category. 

Columns 4 and 5 contain 

maximum and actual number of 

areas in the category. 

Columns 6 and 1 are the 

maximum and actual number 

of line segments. (Note: 

the maximum number of any 

element type within a 

category is 4,770. This 

field is used only during 

initial processing of data). 

32 or 88 spaces 

lThe number of categories •q• is given in record C.l. There will be 56 bytes of data per category, and thus a maximum of 

two categories can be described on a 144 character record. The space filler will vary in size depending on the value of 

•q.• 
N 

....., 

Record 

Number 

D.l 

D.l 

D.l 

D.l 

D.l 

D.2 

D.2 

D.2 

Data 

Element 

1 

2 

3 

4 

5 

1 

2 

3 

APPENDIX A.--standard DLG Distribution Format (Record Contents)--continued 

Logical Record Type D 

Type 

Contents (Fortran Notation) Format 

Type of element 

code 

Element's internal 

identification number 

x,y file coordinate 

of node point or representative point for the 

area element 

Number (t) of classification attributes 

which are attached to 

the node or area element 

(t~) 

ALPHA 

INTEGER*2 

INTEGER*2 

INTEGER*2 

Number (k) of pairs of INTEGER*2 

text characters which are 

attached to the node or 

area element (k~O) 

Filler 

Code indicating a 

line segment graph 

element 

Line segment's internal 

identification number 

Internal identification 

number of starting node 

ALPHA 

INTEGER*2 

INTEGER*2 

A2 

I6 

2I6 

I6 

I6 

A2 

I6 

I6 

Starting Ending 

Byte Byte 

1 2 

3 8 

9 20 

21 26 

27 32 

33 144 

2 

3 8 

9 14 

Comment 

Code ='Nb' for Node element, 

'Ab' for Area element. 

Unique within each category 

and element type. 

The representative area 

point is usually, but not 

always, contained within the 

area it represents. 

Absence of attribute codes 

is indicated by t=O. 

k=O. There are no text 

attributes for 7.5- and 

15-minute DLG data. 

112 spaces 

Code='Lb' for line segment 

This number is unique within 

each category and element 

type. 

Number refers to data 

element 2 in record D.l. 
APPENDIX A.--standard DLG Distribution Format (Record Contents)--continued 

Logical Record Type D--continued 

Record Data Type Starting Ending 

Number Element Contents (Fortran Notation) Format B:t:te B:t:te Comment 

D.2 4 Internal identification INTEGER*2 I6 15 20 Number refers to data 

number of ending node element 2 in record D.l. 

D.2 5 Internal identification INTEGER*2 I6 21 26 Number refers to data 

tv number of left area element 2 in record D.l. (X) 

D.2 6 Internal identification INTEGER*2 I6 27 32 Number refers to data 

number of right area element 2 in record D.l. 

D.2 7 Number (v) of coordinate INTEGER*2 I6 33 38 1500~~2 

pairs which define the 

line segment 

D.2 8 Number (t} of classifi- INTEGER*2 I6 39 44 Absence of classification 

cation attributes which attribute codes is indicated 

are attached to the by t=O. 

line segment (t.?:_()) 

D.2 9 Number (k) of pairs of INTEGER*2 I6 45 50 k=O. There are no text 

text characters which attributes for 7.5- and 

are attached to the 15-minute DLG data. 

line segment (k~O) 

Filler --- --- 51 144 94 spaces 
\D "" 

Record 

Number 

E.l to2 

E.n 

Data 

Element 

1 

APPENDIX A.--standard DLG Distribution Format (Record Contents)--continued 

Logical Record Type E 

Type 

Contents (Fortran Notation) Format 

A (v,2) array contain- INTEGER*2 v(2I6) 

ing an ordered sequence 

of coordinate pairs which 

define the image presentation of a line element 

Filler 

Starting Ending 

BYte Byte 

1 

Comment 

Coordinates are expressed 

in internal file reference 

system, in units of 

thousandths of an incn. 

The array is stored by row. 

0 to 132 spaces 

2The number of coordinate pairs, •v•, is given in record D.2. There will be v(2I6) coordinate pairs of which a maximum of 

12 pairs will fit on a 144 character ASCII record. The space filler will vary in size depending on the value of •v.• If 

•v• equals 12 or is an integer multiple of 12, there will be no spaces as filler at the end of the record. 
w 

0 

Record 

Number 

F.l3 

to F.n 

APPENDIX A.--standard DLG Distribution Format (Record contents)--continued 

Data 

Element 

1 

Logical Record Type F 

Type 

Contents (Fortran Notation) Format 

A (t,2) array containing INTEGER* 2 

major and minor classification codes for a graph 

element 

Filler 

t(2I6) 

Starting Ending 

Byte Byte 

1 

Comment 

The array is stored by row 

with the first column containing the major 

classification attribute, 

and the second column 

containing the minor 

classification attribute. 

0 to 132 spaces 

3The number of feature (attribute) codes, •t• is given in the D.l and D.2 records. The F record is an array of t(2I6) 

codes of which a maximum of 12(2I6) will fit on a 144 character ASCII record. The space filler will vary depending on the 

value of •t•. If •t• is 12 or an integer multiple of 12 there will be no spaces as filler at the end of the record. 
APPENDIX B.--Optional DLG Distribution Format 

(Record Contents) 

In the optional DLG distribution format, topological linkages are 

explicitly encoded for node and area elements as well as for line 

elements. The files are physically comprised of 8-bi t ASCII characters 

organized into fixed length logical records of 80 characters (bytes). 

Bytes 1-72 of each record contain DLG data, and bytes 73-80 contain a 

record sequence number. 

The 11 distinct record types used in the optional DLG distribution 

format may be categorized as header and data records. 

Four types of records are considered header records: 

• File identification and description records 

• Accuracy records (not currently used) 

• Control-point identification records 

• Data-category identification records 

Seven types of records are considered data records: 

• Node and area identification records 

• Node-to-line linkage records 

• Area-to-line linkage records 

• Line identification records (also contains line-to-node and 

line-to-area linkages) 

• Coordinate string records 

• Attribute code records 

• Text records (not currently used) 

31 
APPENDIX B.--optional DLG Distribution Format 

(Record Contents)--continued 

The actual sequence of records in an optional distribution format DLG 

file is as follows: 

1. Header records 

2. 

Ten file identification and 

description records 

Accuracy records (not currently used) 

Control point identification records 

(one per control-point) 

Data category identification records 

(one per data category in the file) 

Data records I Node identification record 

Node-to-line linkage record(s) 

Attribute code record(s) 

Text record(s) 

Area identification record I Area-to-line linkage record(s) 

Attribute code record(s) 

Text record(s) 

Line identification records I Coordinate string record(s) 

Attribute code record ( s) 

Text record(s) 

Repeated 

for each 

node within a 

data category 

Repeated Repeated 

for each for each 

area within a data category 

data category 

Repeated 

for each 

line within a 

data category 

Descriptions of the contents of the various types of records in an 

optional distribution format DLG are contained in the following tables. 

32 
w 

w 

Record 

Number 

1 

2 

2 

2 

3 

4 

4 

4 

Data 

Element 

1 

1 

2 

3 

1 

2 

3 

APPENDIX B.--Optional DLG Distribution Format (Record Contents)--continued 

FILE IDENTIFICATION AND DESCRIPTION RECORDS 

Type 

Contents (Fortran Notation) Format 

Banner 

Name of Digital 

Cartographic Unit 

Filler 

Date of original 

source material 

Filler 

Scale of original 

source material 

Filler 

Filler 

DLG level code 

Code defining ground 

planimetric reference 

system 

Code defining zone in 

ground planimetric 

reference system 

ALPHA A72 

ALPHA A40 

ALPHA AlO 

INTEGER*4 IS 

INTEGER*2 I6 

INTEGER*2 I6 

IN'I'EGER*2 I6 

Starting Ending 

Byte Byte 

1 72 

1 40 

41 41 

42 51 

52 52 

53 60 

61 72 

1 72 

1 6 

7 12 

13 18 

Comment 

Descriptive text. 

The name of the map will be 

used when practical. 

1 space 

Year of original source 

material followed by latest 

photorevision date if 

applicable, for example, 

1956, 1965. 

1 space 

Scale denominator of source 

material, for example, 

62500 

12 spaces 

72 spaces. This record is 

not currently used. 

Code=3, DLG-3 

Code=!, UTM 

Codes for UTM coordinate 

zones are given in appendix 

c. 
APPENDIX B.--optional DLG Distribution Format (Record Contents)--continued 

FILE IDENTIFICATION AND DESCRIPTION RECORDS--continued I 

Record Data Type Starting Ending 

Number Element contents (Fortran Notation) Format B:t:te B:t:te Comment 

4 4 Code defining units INTEGER*2 I6 19 24 Code=2, meters 

of measure for ground 

planimetric coordinates 

throughout the file 

4 5 Resolution REAL*4 Dl8.11 25 42 The true ground distance 

corresponding to one unit 

(0.001 inch at map scale) 

in the file internal coordinate system used in data 

w collection. This value 

~ corresponds to the scale 

of the source document as 

follows: 

scale Resolution 

1:24,000 0.61M 

1:25,000 0.63M 

1:48,000 1.22M 

1:62,500 1.58M 

4 6 Number of file-to- INTEGER*2 I6 43 48 Usually 4. 

map transformation 

parameters 

4 7 Number of accuracy/ INTEGER*2 I6 49 54 currently=O, none included 

miscellaneous records 

4 8 Number (n) of sides INTEGER*2 I6 55 60 Usually 4. 

in the polygon which 

define the coverage of 

the cell. Number (n) 

also defines the number of 

control-points 
w 

U'l 

Record 

Number 

4 

5-9 

10 

Data 

Element 

9 

1 

1 

APPENDIX B.--Optional DLG Distribution Format (Record Contents)--continued 

FILE IDENTIFICATION AND DESCRIPTION RECORDS--continued 

Type 

Contents (Fortran Notation) Format 

Number (q) of categories INTEGER*2 

(overlays) in the DLG 

file 

Filler ---

Projection parameters REAL*8 

for map transformation 

Internal file-to- REAL*4 

map projection 

transformation 

parameters 

I6 

---

3D24.15 

4Dl8 .11 

Starting Ending 

Byte Byte 

61 66 

67 72 

1 72 

1 72 

Comment 

l~q~32. Up to 32 categories can be represented 

in a given file. The value 

will usually be between 

1 and 5. 

6 spaces 

Three parameters on each of 

5 records. Parameters for 

the UTM projection are 

given in Appendix c. 

A transformation of this 

type is not required, since 

coordinates are expressed 

in a ground planimetric 

coordinate system (usually 

UTM). These parameters are 

however, valid for transformation as described in 

record B.l, data element 1, 

of the standard format. 
APPENDIX B.--Optional DLG Distribution Format (Record Contents)--continued 

CONTROL-POINT IDENTIFICATION RECORDS 

Record Data Type Starting Ending 

Number Element contents (Fortran Notation) Format B~te B~te comment 

1-n 1 Control-point label ALPHA A2 1 2 •sw,• •NW,• •NE,• or •sE• 

for four quadrangle 

corners. 

Filler 3 6 4 spaces 

2 Latitude REAL*4 Fl2.6 7 18 In degrees and decimal 

degrees. 

w 

Cl'l 3 Longitude REAL*4 Fl2.6 19 30 In degrees and decimal 

degrees. 

Filler 31 36 6 spaces 

4 Internal file x REAL*4 Fl2.2 37 48 In units in the appropriate 

zone of the ground planimetric coordinate system. 

5 Internal file y REAL*4 Fl2.2 49 60 In units in the appropriate 

zone of the ground planimetric coordinate system. 

Filler --- --- 61 72 12 spaces 
w 

-..,J 

Record 

Number 

1-q 

Data 

Element 

1 

2 

3 

4 

5 

6 

7 

APPENDIX B.--optional DLG Distribution Format (Record Contents)--continued 

DATA CATEGORY IDENTIFICATION RECORDS 

Type 

Contents (Fortran Notation) Format 

category name 

Attribute format codes 

Number of nodes referenced in file 

Actual number of 

nodes in file 

Filler 

Presence of node-toarea linkage records 

Presence of node-toline linkage records 

Filler 

Number of areas referenced in file 

ALPHA A20 

INTEGER*2 I4 

INTEGER*2 I6 

INTEGER*2 I6 

INTEGER*2 Il 

INTEGER*2 Il 

INTEGER*2 I6 

Starting Ending 

Byte Byte 

1 20 

21 24 

25 30 

31 36 

37 37 

38 38 

39 39 

40 40 

41 46 

comment 

The first 4 characters are 

unique. 

Blank or zero (0) indicates 

default (2I6) attribute 

formatting in major-minor 

pairs. 

Number of nodes referenced 

in file as start and end 

nodes of lines. 

Only if some or all node 

records were excluded from 

the file, would this number 

be different from data 

element 3. 

1 space 

Flag=O, node-to-area 

linkage records not 

present. I 

Flag=!, node-to-line 

linkage records are 

included.! 

1 zero or space 

Number of areas referenced 

in file as areas left and 

areas right of lines. 

1The flags for lists present or absent are the current default values, and are the only current values used. 
w 

0) 

Record 

Number 

Data 

Element 

8 

9 

10 

11 

12 

13 

14 

APPENDIX B.--Optional DLG Distribution Format (Record Contents)--continued 

DATA CATEGORY IDENTIFICATION RECORDS--continued 

Type 

Contents (Fortran Notation) Format 

Actual number of areas 

in file 

Filler 

Presence of area-tonode linkage records 

Presence of area-toline linkage records 

Presence of areacoordinate lists 

Number of lines 

referenced in file 

Actual number of 

lines in file 

Filler 

Presence of linecoordinate lists 

INTEGER*2 I6 

INTEGER*2 Il 

INTEGER*2 Il 

INTEGER*2 Il 

INTEGER*2 I6 

INTEGER*2 I6 

INTEGER*2 Il 

Starting Ending 

Byte Byte 

47 52 

53 53 

54 54 

55 55 

56 56 

57 62 

63 68 

69 71 

72 72 

Comment 

Only if some or all area 

records were excluded from 

the file would the number 

be different from the data 

element 7. 

1 space 

Flag=O, area-to-node 

linkage records not 

present. I 

Flag=l, area-to-line 

linkage records are 

included.! 

Flag=O, area-coordinate 

lists not present.! 

Number of lines referenced 

in area-to-line and nodeto-line records. 

Only if some lines were 

excluded from the file 

would this number be 

different from data element 

12. 

3 spaces 

Flag=!, line-coordinate 

lists are included.! 

1The flags for lists present or absent are the current default values, and are the only current values used. 
w 

\0 

Record 

Number 

Data 

Element 

1 

2 

3 

4 

5 

6 

7 

8 

9 

APPENDIX B.--Optional DLG Distribution Format (Record Contents)--continued 

NODE AND AREA IDENTIFICATION RECORDS 

Type 

Contents (Fortran Notation) Format 

Record type 

Element internal 

ID number 

Coordinates of node 

point or representative 

point for area 

ALPHA 

INTEGER*2 

REAL*4 

Number of elements in INTEGER*2 

an area list (for nodes), 

or in a node list 

(for areas) 

Number of elements in 

line segment list 

Number of x,y or 

lat-long points 

in area-coordinate 

list 

Number of attributes 

listed 

Number of text 

characters listed 

Number of islands 

within area 

Filler 

INTEGER*2 

INTEGER*2 

INTEGER*2 

INTEGER*2 

INTEGER*2 

Al 

IS 

2Fl2.2 

I6 

I6 

I6 

I6 

I6 

I6 

Starting Ending 

Byte Byte 

1 1 

2 6 

7 30 

31 36 

37 42 

43 48 

49 54 

55 60 

61 66 

67 72 

Comment 

•N• or •A• 

This value is unique within 

each category and element 

type. 

The area point is usually, 

but not always within the 

polygon it represents. 

Blank or zero (0). These 

lists are not currently 

included. 

Number of line segments 

that intersect at the node, 

or bound the area. 

Blank or zero (0). These 

lists are not currently 

included. 

Number of attributes 

listed. 

Zero (0). There are no 

text attributes for 7.5-

and 15-minute DLG data. 

Area records only, 6 spaces 

for node records. 

6 spaces 
ol:oo 

0 

APPENDIX B.--Optional DLG Distribution Format (Record Contents)--continued 

NODE-TO-LINE LINKAGE RECORDS 

FORTRAN FORMAT (12I6), for each node: The list consists of line segment int'rnal ID numbers (which appear in bytes 2-6 of 

the line iqentification records). The line segments which begin at this node are included in the list as positive ID 

numbers. The line segments which terminate at this node are included as negative ID numbers. There is no logical order to 

the list. 

AREA-TO-LINE LINKAGE RECORDS 

FORTRAN format (1216), for each area: The list consists of line segment internal ID numbers (which appear in bytes 2-6 of 

the line identification records) and, for those areas with islands (indicated by bytes 61-66 of the area's first record), 

zero (0) elements marking the beginning of islands. Line segments with this area to the right are included as positive ID 

numbers. Line segments with this area to the left are included as negative ID numbers. The list is ordered clockwise 

around the perimeter of the area and counterclockwise around each island, if any (counterclockwise around an island of an 

area is still a clockwise direction in reference to the area itself). A zero (0) ~lement is inserted in the list before 

each island sublist. 
APPENDIX B.--optional DLG Distribution Format (Record Contents)--continued 

LINE IDENTIFICATION RECORDS 

Record Data Type Starting Ending 

Number Element Contents (Fortran Notation) Format B~te B~te Comment 

1 Record type Al 1 1 •L• 

2 Element internal ID number IS 2 6 This number is unique within 

each category and element 

type. 

3 starting node I6 7 12 Internal ID number. This 

refers to data element 2 of 

the node identification 

record. 

4 Ending node I6 13 18 Internal ID number. This 

~ refers to data element 2 of ...... the node identification 

record. 

5 Left area I6 19 24 Internal ID number. This 

refers to data element 2 of 

the area identification 

record. 

6 Right area I6 25 30 Internal ID number. This 

refers to data element 2 of 

the area identification 

record. 

Filler --- 31 42 12 spaces 

7 Number of x,y coordinates I6 43 48 Number of coordinate 

listed pairs listed. 

8 Number of attributes listed I6 49 54 Number of attributes (or two 

element attribute pairs) 

listed. 

9 Number of text characters listed I6 55 60 Zero (0). There are no text 

data associated with 7.5-

and 15-minute DLG data. 
~ 

N 

APPENDIX B.--Optional DLG Distribution Format (Record contents)--continued 

COORDINATE STRING RECORDS 

FORTRAN format (3(2Fl2.2)): The coordinates are in appropriate units in the designated ground planimetric coordinate 

system (usually meters in UTM). The file-to-map projection parameters in Header record 10 are set to (l.O,o.o,o.o,o.o) for 

real map projection coordinates (the transformation formulas still apply). 

CODE RECORDS 

As major-minor code attribute pairs, FORTRAN format (6(2I6)): Within each pair, the first integer is the major code and 

the second integer is the minor code. Each major and minor code is a one-to-four-digit integer, right justified within the 

six-byte field. 
APPENDIX C.--Map Projection Parameters 

Universal Transverse Mercator (UTM) 

The standard and optional DLG distribution formats include 15 fields 

reserved for map projection parameters. These parameters are typically 

used as input for a coordinate transformation package such as the USGS 

General Cartographic Transformation Package (GCTP). 

When the ground planimetric coordinate system of a DLG is the 

Universal Transverse Mercator system, as in the case for all DLG's 

digitized from 1:24,000-scale maps, .only the first two of the 15 

parameter fields are used: 

1. 

2. 

3-15. 

Longitude of any point in UTM zone. 

Latitude of any point in UTM zone. 

Not used (=0). 

Normally placed at the 

center of the DLG cell. 

A transformation to or from UTM using GCTP can be controlled by 

specifying the UTM zone or by supplying the geographic coordinate in 

parameters 1 and 2, from which the UTM zone is computed by GCTP. In a 

DLG file, the parameters are encoded as packed, degrees-minutes-seconds 

(DMS) as follows: 

degrees * 1000000 + minutes * 1000 + seconds 

Example: If degrees = +50, minutes = 30, and seconds = 36.25, then the 

parameter value is 50030036.25 stored as a REAL*S variable, and 

•bb0.500300362500000D OS• encoded in FORTRAN D24.15 format. 

43 
APPENDIX C.--Map Projection Parameters 

Universal Transverse Mercator (UTM)--continued 

Codes for UTM Coordinate zones 

West Longitude (degrees) ~ 

180-17 4 1 

174-168 2 

168-162 3 

162-156 4 

156-150 5 

150-144 6 

144-138 7 

138-132 8 

13 2-126 9 

126-120 10 

120-114 11 

114-108 12 

108-102 13 

102- 96 14 

96- 90 15 

90- 84 16 

84- 78 17 

78- 72 18 

72- 66 19 

66- 60 20 

44 
APPENDIX D.--DLG Attribute Codes 

Valid Minor Codes for the Coincident Feature Parameter 

0003 

0004 

0005 

0009 

0010 

0011 

0030 

Base Category 

Hydrography; 

Streams, rivers, irrigation channels or canals, ditch~s 

Lakes, ponds, reservoirs, springs, wells, glaciers, and 

snowfields 

Combined Hydrography 

Boundaries 

Transportation Systems 

Roads and trails 

Railroads 

Public Land Survey System 

45 
~ 

0'1 

DATA CATEGORY 

combined Hydrography 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE APPLICATION 

Feature identification Nodes 

Areas 

Lines 

MAJOR 

CODE 

050 

000 

050 

MINOR 

CODE 

0001 

0002 

0003 

0004 

0005 

0000 

0100 

0101 

0102 

0103 

0104 

0105 

0106 

0107 

0108 

0109 

DESCRIPTION 

Upper origin of stream 

Upper origin of stream at water body 

Sink 

stream entering water body 

Stream exiting water body 

Area outside graph 

Alkali flat 

Reservoir 

Covered reservoir 

Glacier or permanent snowfield 

Salt evaporator 

Inundation area 

Fish hatchery or farm 

Industrial water impoundment 

Area to be submerged 

sewage disposal pond or 

filtration beds 

0110 Tailings pond 

0111 Marsh, wetland, swamp, bog 

0112 Mangrove area 

0113 Rice field 

0114 Cranberry bog 

0115 Flats (tidal, mud, sand, gravel) 

0116 Bays, estuaries, gulfs, oceans, seas 

0200 

0201 

0202 

0203 

0204 

0205 

Shoreline 

Manmade shoreline 

Closure line, (water-water) 

Indefinite shoreline 

Apparent limit 

Outline of a Carolina bay 
~ 

...... 

DATA CATEGORY 

Combined Hydrography 

(cont'd.) 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

APPLICATION 

Points 

(Degenerate Lines) 

Multiple Element 

Types 

MAJOR MINOR 

CODE 

050 

050 

CODE 

0300 

0301 

0302 

0303 

0304 

0305 

0000 

0400 

0401 

0402 

0403 

0404 

0405 

0406 

0407 

0408 

0409 

0410 

0411 

0412 

0413 

0414 

0415 

0416 

0417 

0418 

0419 

0420 

0421 

0422 

DESCRIPTION 

Spring 

Non-flowing well 

Flowing well 

Riser 

Geyser 

Windmill 

Feature added by photorevision 

methods 

Rapids 

Falls 

Gravel pit or quarry filled with water 

Gaging station 

Pumping station 

Water intake 

Darn or weir 

Canal lock or sluice gate 

Spillway 

Gate (flood, tidal, head, check) 

Exposed rock 

Crevasse 

Stream 

Braided stream 

Ditch or canal 

Aqueduct 

Flume 

Penstock 

Siphon 

Channel in water area 

Wash or ephemeral drain 

Lake or pond 

Coral reef 
.a:. 

(X) 

DATA CATEGORY 

Combined Hydrography 

{cont'd.) 

TYPE OF CODE 

Descriptive 

Parameter 

APPENDIX D.--DLG Attribute Codes--continued 

APPLICATION 

Multiple Element 

Types 

Multiple Element 

Types 

MAJOR 

CODE 

050 

OSN 

055 

058 

059 

MINOR 

CODE 

0601 

0602 

0603 

0604 

0605 

0606 

0607 

0608 

0609 

0610 

0611 

0612 

0613 

0614 

0615 

0616 

0617 

0618 

0000 

00--

DESCRIPTION 

Underground 

overpassing 

Elevated 

Tunnel 

Right bank 

Left bank 

Under construction 

Salt 

Unsurveyed 

Intermittent 

Abandoned 

Submerged 

Wooded 

Dry 

Mineral or hot {sulphur, alkali, etc.) 

Navigable transportation 

Underpassing 

Earthen construction 

Water surface elevation 

N=l for feet, 2 for meters, 6 for 

feet below datum, and 7 for meters 

below datum. Elevation value in four 

spaces, right justified. 

River mile, value in four spaces, 

right justified 

Best estimate of classification 

and/or position 

Coincident feature {enter first two 

digits of major code for category of 

coincident feature in blanks, right 

justified. 
1.0 ""' 

DATA CATEGORY 

Boundaries 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE APPLICATION 

Feature identification Nodes 

Areas 

MAJOR 

CODE 

090 

000 

090 

MINOR 

CODE 

0001 

0002 

0000 

0100 

0101 

0103 

0104 

0105 

0106 

0107 

0108 

0109 

OllO 

0113 

0130 

0131 

0132 

0133 

0134 

0150 

0151 

0197 

0198 

0199 

DESCRIPTION 

Boundary, monumented point on boundary 

Boundary, turning point 

(all within United States unless 

otherwise indicated) 

Area outside graph 

Boundary, civil township, district, 

precinct, barrio 

Boundary, incorporated city, village, 

town, borough or hamlet 

Boundary, national park, monument, 

lakeshore, parkway, battlefield or 

rec. area 

Boundary, national forest or grassland 

Boundary, national wildlife refuge, 

game preserve, or fish hatchery 

Boundary, national scenic waterways or 

wilderness area 

Boundary, Indian reservation 

Boundary, military reservation 

Boundary, non-military government 

reservation 

Boundary, Federal prison 

Boundary, land grant 

Boundary, State park, rec. area, or 

State lake 

Boundary, State wildlife refuge/game 

preserve 

Boundary, State forest 

Boundary, State prison 

Boundary, county game preserve 

Boundary, large city, county, or 

private park 

Boundary, small park 

Boundary, Canada 

Boundary, Mexico 

Boundary, area outside a national 

boundary 
U"' 

0 

DATA CATEGORY 

Boundaries (cont'd.) 

Transportation, Roads 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

Parameter 

Feature identification 

APPLICATION 

Lines 

Points 

(Degenerate Lines) 

Multiple Element 

Types 

Nodes 

MAJOR 

CODE 

090 

090 

091 

092 

095 

098 

099 

100 

MINOR 

CODE 

0200 

0201 

0202 

0203 

0301 

00--

0---

0000 

00--

0001 

0002 

0003 

0004 

0005 

0006 

0007 

0008 

DESCRIPTION 

Boundary, approximate boundary 

Boundary, indefinite boundary (shown 

by normal symbolization at 1/2 

specified line weight for county 

boundary and higher rank) 

Boundary, disputed boundary 

Boundary, historical line 

Reference monuments for turning points 

Boundary, enter State FIPS code in two 

digits right justified 

Boundary, enter county or county 

equivalent FIPS code in three digits 

right justified 

Boundary, monument number, one to four 

digits, right justified 

Best estimate of classification and/or 

position 

Boundary, coincident feature (enter 

first two digits of major code for 

category of coincident feature in 

blanks, right justified) 

Road intersection 

Road intersection (grade separation, 

no interchange) 

Road intersection (grade separation 

with interchange) 

Road intersection (grade separation, 

partial interchange) 

Road-railroad intersection 

Road-railroad intersection (grade 

separation) 

Road-stream intersection (fixed 

bridge/culvert) 

Road-stream intersection 

(movable bridge) 
U1 

..... 

DATA CATEGORY 

Transportation, Roads 

(cont'd.) 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE APPLICATION· 

Feature identification Nodes (cont 'd.) 

Areas 

Lines 

MAJOR MINOR 

CODE 

100 

000 

100 

CODE DESCRIPTION 

Road-trail intersection 

Trail-trail intersection 

Bridge abutment 

Tunnel portal 

0009 

0010 

0011 

0012 

0013 Road-transmission line intersection 

0014 Road-pipeline intersection 

0015 Ferry landing 

0016 Change in road classification/status 

0017 Structure over road 

0018 Ford 

0019 Low water bridge 

0020 Toll gate 

0021 Traffic circle 

0022 Cul-de-sac 

0023 Gate 

0024 Road-canal intersection (where canal 

0030 

0050 

0051 

is a transportation feature) 

Foot or bicycle bridge over road 

Point on road 

End of road/trail 

0060 Port of entry 

0061 u.s. customs 

0000 Area outside graph 

N201 Primary route, hard surface 

(undivided) 

N202 Primary route, hard surface 

25' or less) 

N203 Primary route, hard surface 

25' or more) 

N204 Primary route, hard surface 

traffic) 

(divided, 

(divided, 

(one-way 

N205 Secondary route, hard surface (one-way 

traffic) 

N206 Secondary route, hard surface 

N207 Improved light duty 

N208 Unimproved dirt 

N209 Trail 
l1l 

N 

DATA CATEGORY 

Transportation, Roads 

(cont'd.) 

APPENDIX D.--DLG Attribute Codes--continued 

MAJOR 

TYPE OF CODE APPLICATION CODE 

Feature identification Lines (cont 'd.) 100 

Points 100 

(Degenerate Lines) 

MINOR 

CODE 

N210 

N211 

N212 

N213 

N214 

N215 

N216 

N217 

N218 

N219 

N220 

N222 

N223 

N240 

N241 

N250 

N293 

N294 

N295 

N296 

N297 

N298 

N299 

0301 

0302 

0303 

0304 

0305 

DESCRIPTION 

4-wheel-drive vehicle trail 

Urban streets 

Foot trail 

Bridle trail 

Pack trail 

Historical trail 

Bicycle trail 

Primary route, hard surface 

(interchange road) 

Secondary route, hard surface 

(interchange road) 

Improved light duty interchange road 

Secondary route, divided 

Road or street, class 3, divided by 

centerline 

Road or street, class 3, divided, 

lanes separated 

Ferry crossing 

Road through parking area 

Perimeter of parking area 

Road or trail subject to inundation 

Road or trail on dam 

Road or trail 

Road or trail 

Road or trail 

Road or trail 

Road or trail 

on bridge 

on levee 

tunnel under ground 

tunnel under water 

under construction 

N=O for unrestricted access, N=l for 

limited access, N=2 for toll road, 

N=3 for privately operated or 

controlled public access, N=4 for 

proposed road, N=5 for abandoned road 

Roadside or wayside park 

Rest area 

overlook 

Weigh station 

Service facility 
l11 

w 

DATA CATEGORY 

Transportation, Roads 

(cont'd.) 

Transportation, 

Railroads 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

Parameter 

Feature identification 

APPLICATION 

Multiple Element 

Types 

Multiple Element 

Types 

Nodes 

MAJOR 

CODE 

100 

101 

102 

103 

104 

105 

106 

108 

109 

110 

MINOR 

CODE 

0000 

00--

0---

0---

0000 

0---

0001 

0002 

0003 

0004 

DESCRIPTION 

Feature added by photorevision methods 

Number of lanes, right justified 

Interstate route number, right 

justified 

u.s. route number, right justified 

State route number, right justified 

Reservation, park, or military route 

number, right justified 

County route number, right justified 

Best estimate of classification and/or 

position 

Coincident feature or symbol (enter 

first two digits of major code for 

category of coincident feature in 

blanks, right justified) 

Railroad intersection 

Railroad intersection (grade 

separation) 

Siding junction 

Station 

0005 Railroad-road intersection 

0006 Railroad-road intersection (grade 

separation) 

0007 Railroad-stream intersection (fixed 

bridge/culvert) 

0008 Railroad-stream intersection (movable 

bridge) 

0009 Railroad-trail intersection 

0010 Bridge abutment 

0011 Tunnel portal 

0012 Railroad-transmission line 

intersection 

0013 Railroad-pipeline intersection 

0014 Ferry landing 
U1 

~ 

DATA CATEGORY 

Transportation, 

Railroads (cont'd.) 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE APPLICATION 

Feature identification Nodes (cont 'd.) 

Areas 

Lines 

MAJOR 

CODE 

l10 

000 

l10 

MINOR 

CODE 

0015 

DESCRIPTION 

Change in railroad classification/ 

status 

0016 Structure over railroad 

0017 Turntable 

0018 Turntable and roundhouse 

0019 Point within yard 

0049 Crossover 

0050 Point on railroad 

0051 End of railroad 

0000 

N201 

N202 

N203 

N204 

N205 

N206 

N211 

N212 

N213 

N214 

N215 

.N216 

N220 

N221 

N230 

Area outside graph 

Single track standard gage 

Double track, standard gage 

3-track, standard gage 

4-track, standard gage 

5 or more tracks, standard gage 

Siding, standard gage 

Single track, narrow gage 

Double track, narrow gage 

3-track, narrow gage 

4-track, narrow gage 

5 or more tracks, narrow gage 

Siding, narrow gage 

Carline or surface rapid transit 

Elevated rapid transit 

Industrial or mine railroad 

N240 Ferry crossing 

N241 Railroad through yard 

N250 Perimeter of yard 

N294 Railroad on pier 

N295 Railroad on bridge 

N296 Railroad on levee 

N297 Railroad tunnel under ground 

N298 Railroad tunnel underwater 

N299 Railroad in snowshed 

N=O for normal use, N=l for under 

construction, N=2 for abandoned, 

N=3 for dismantled 
01 

01 

DATA CATEGORY 

Transportation 

Railroads (cont 'd.) 

Pipelines, 

Transmission Lines 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

Parameter 

Feature identification 

APPLICATION 

Points 

(Degenerate Lines) 

Multiple Element 

Types 

Multiple Element 

Types 

Nodes 

MAJOR 

CODE 

NONE 

110 

118 

119 

130 

MINOR 

CODE 

0000 

0000 

00--

0001 

0002 

0003 

0004 

0005 

0006 

0007 

0008 

0009 

0010 

0011 

0012 

0013 

0014 

0015 

0016 

0020 

0030 

0031 

DESCRIPTION 

Feature added by photorevision methods 

Best estimate of classification and/or 

position 

Coincident feature or symbol (enter 

first two digits of major code for 

category of coincident feature, 

right justified). 

Transmission line intersection 

Pipeline intersection 

Transmission line - pipeline 

intersection 

Transmission line - road intersection 

Pipeline - road intersection 

Transmission line - railroad 

intersection 

Pipeline - stream intersection 

Transmission line - stream 

intersection 

Pipeline - stream intersection 

Transmission line - telephone/ 

telegraph line intersection 

Pipeline - bank/shore intersection 

Transmission line - telephone/ 

telegraph line intersection 

Pipeline - telephone/telegraph line 

intersection 

Pumping station 

Substation 

Steel tower 

Change in classification/status 

Angle point on transmission line 

Angle point on pipeline 
(Jl 

0'\ 

DATA CATEGORY 

Pipelines, 

Transmission Lines 

(cont 'd.) 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

APPLICATION 

Nodes (cont 'd.) 

Areas 

Lines 

Points 

Multiple Element 

Types 

MAJOR 

CODE 

130 

000 

130 

NONE 

130 

MINOR 

CODE 

0032 

0033 

0034 

0035 

0036 

DESCRIPTION 

Point on transmission line 

Point on pipeline 

End of transmission line 

End of pipeline 

End of transmission line at power 

station or substation 

0037 End of pipeline at refinery/oil-gas 

field 

0000 

0201 

0202 

0203 

0204 

0205 

0206 

0211 

0212 

0213 

0214 

0215 

0216 

0217 

0221 

0000 

Area outside graph 

Single or double pole powerline 

Steel tower powerline 

Single or double pole powerline 

extended over water 

Steel tower powerline Pxtended over 

water 

Single or double pole powerline 

extended into urban area 

Steel tower powerline extended into 

urban area 

Pipeline (under ground) 

Pipeline (above ground) 

Pipeline (under water) 

Pipeline (above water) 

Pipeline, through siphon 

Pipeline, through flume 

Pipeline extended into urban area 

Telephone or telegraph line 

Feature added by photorevision methods 
l11 

-...1 

DATA CATEGORY 

Pipelines, 

Transmission Lines 

(cont'd.) 

u.s. Public Land 

survey Data 

APPENDIX D.--DLG Attribute Codes--continued 

MAJOR MINOR 

TYPE OF CODE APPLICATION CODE CODE 

Parameter Multiple Element 138 0000 

Types 

139 00--

139 01--

Feature identification Nodes 300 0001 

0002 

0003 

0004 

0005 

0006 

0007 

0008 

0009 

0010 

0011 

0012 

0013 

0014 

0015 

0040 

0041 

0042 

DESCRIPTION 

Best estimate of classification and/or 

position 

Coincident feature or symbol (enter 

first two digits of major code for 

category of coincident feature, right 

justified). 

Assumed position next to parallel 

feature or symbol (enter first two 

digits of major code for category of 

parallel feature, right justified). 

u.s. Public Land Survey section corner 

Point on section line (no corner) 

Closing corner 

Meander corner 

Auxiliary meander corner 

Special meander corner 

Witness corner 

Witness point 

Angle point 

Location monument (includes amended 

monument and mineral monument) 

Reference mark 

Quarter-section corner 

Tract corner 

Land grant corner 

Arbitrary section corner 

Identification procedure, corner 

identified in field 

Identification procedure, corner 

with horizontal coordinates 

Identification procedure, corner with 

elevation value 
LT1 

00 

DATA CATEGORY 

u.s. Public Land 

survey Data 

(cont 'd.) 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE APPLICATION 

Parameters Areas 

MAJOR 

CODE 

000 

301 

307 

30-

MINOR 

CODE 

0000 

0---

DESCRIPTION 

Area outside graph 

Select one parameter code from each of 

the following A, B, c, and D lists 

and/or consult list E 

A. Section number or Land Grant no. 

Insert 0 in the first space for 

numeric section identifier, 1 for 

numeric portion of alphanumeric 

identifier, or 2 for alphabetic part 

of alphanumeric identifier. In the 

last three spaces, insert section 

number or numeric representation of 

alphabetic character (01-26), right 

justified. 

Insert 0 in the first space for 

numeric grant identifier, 1 for 

numeric portion of alphanumeric 

identifier, 2 for alphabetic portion 

of alphanumeric identifier, or 3 for 

alphabetic identifier. In the last 

three spaces, insert grant number or 

numeric representation of alphabetic 

character (01-26), right justified. 

B. Township number(s) 

Insert 2 for north of the baseline or 

3 for south of the baseline in first 

space. In the second space, insert 

a 0 for full township 2 for 1/4 

township, 4 for 1/2 township, or 6 

for 3/4 township. Insert township 

number in the last three spaces, 

right justified. 
(Jl 

\0 

DATA CATEGORY 

u.s. Public Land 

survey Data 

(cont'd.) 

TYPE OF CODE 

Parameters 

APPENDIX D.--DLG Attribute Codes--continued 

APPLICATION 

Areas (cont'd.) 

MAJOR 

CODE 

30-

30-

306 

MINOR 

CODE DESCRIPTION 

00--

0001 

0002 

0003 

0004 

0046 

0005 

0006 

0007 

0008 

0009 

0010 

0011 

0012 

0013 

0014 

0015 

0016 

0017 

c. Range number(s) 

Insert 4 for east of the principal 

meridian or 5 for west of the 

principal meridian in the first 

space. In the second space, insert 

a 0 for a full range, for 1/4 range, 

4 for 1/2 range, 6 for 3/4 range, 8 

for duplicate to the north or east 

of the original township, or 9 for 

triplicate to the north or east of 

the original township. Insert range 

number in last three spaces, right 

justified. 

D. Origin of survey 

Insert code number from following 

list. 

1st Principal Meridian 

2nd Principal Meridian 

3rd Principal Meridian 

4th Principal Meridian (IL) 

4th Principal Meridian (MN&WI) 

5th Principal Meridian 

6th Principal Meridian 

Black Hills 

Boise 

Chickasaw 

Choctaw 

Cimarron 

Copper River 

Fiarbanks 

Gila and Salt River 

Humboldt 

Huntsville 

Indiana 
0'\ 

0 

DATA CATEGORY 

u.s. Public Land 

Survey Data 

(cont'd.) 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE APPLICATION 

Parameters (cont'd.) Areas (cont 'd.) 

MAJOR MINOR 

CODE 

306 

306 

CODE 

0018 

0019 

0020 

0021 

0022 

0023 

0024 

0025 

0026 

0027 

0028 

0029 

0030 

0031 

00--

DESCRIPTION 

D. Origin of survey (cont'd.) 

Louisiana 

Michigan 

Principal 

Mount Diablo 

Navajo 

New Mexico Principal 

St. Helena 

St. Stephens 

Salt Lake 

San Bernard 

Seward 

Tallahasee 

Uintah 

Ute 

Insert code number from following 

list. 

0032 Washington 

0033 Willamette 

0034 Wind River 

0035 Ohio River Survey 

0036 Between the Miamis 

0037 Muskingum River 

0038 Ohio River Base 

0039 First Scioto River 

0040 Second Scioto River 

0041 Third Scioto River 

0042 Ellicott's Line (note 1) 

0043 Twelve-Mile Square 

0044 Kateel River 

1. Ellicott's Line is the name given to the Ohio-Pennsylvania boundary. No townships are referenced to Ellicott's Line--it 

is included for compatibility with the BLM. 
0'1 

...... 

DATA CATEGORY 

u.s. Public Land 

Survey Data 

(cont 'd.) 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE APPLICATION 

Parameters (cont'd.) Areas (cont 'd.) 

Feature identification Lines 

MAJOR 

CODE 

306 

300 

300 

MINOR 

CODE 

0045 

0046 

0047 

0048 

0099 

0100 

0101 

0102 

0103 

0104 

0105 

0106 

0107 

0198 

0199 

0201 

0202 

0203 

0204 

DESCRIPTION 

D. Origin of survey (cont'd.) 

Umiat 

Fourth Principal 

West of the Great Miami 

u.s. Military Survey 

Not Public Land Survey (note 2) 

E. If the area has not been surveyed 

as part of the u.s.Public Land survey 

System, the following codes should be 

used. 

Indian lands 

Homestead entries 

Donation land claims 

Land grants; civil colonies 

Private extension of public land 

survey 

Area of public and private survey 

overlap 

Overlapping land grants 

Military reservation 

Water 

Unsurveyed area 

Approximate position (within 200 feet) 

Protracted position 

Arbitrary closure line 

Base line 

2. This code is included for compatibility with the BLM. It refers to area in the original 13 States, Texas, or a 

territory. The PLSS data category is not digitized in these areas. 
0'1 

tv 

DATA CATEGORY 

u.s. Public Land 

survey Data 

(cont 'd.). 

APPENDIX D.--DLG Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

Parameter 

APPLICATION 

Points 

(Degenerate lines) 

Multiple Element 

Types 

MAJOR 

CODE 

0300 

308 

309 

MINOR 

CODE DESCRIPTION 

E. If the area has not been surveyed 

as part of the u.s.Public Land Survey 

System, the following codes should be 

used--continued. 

0300 Location monument 

0301 Isolated found section corner 

0302 Witness corner (off surveyed line) 

0000 

00--

In addition to the parameter codes 

used for designating the section, 

township,and range numbers, the 

following codes may be used. 

Best estimate of classification and/or 

position 

Coincident feature or symbol (enter 

first two digits of major code for 

category of coincident feature in 

blanks, right justified). 
APPENDIX E.--Coordinate Conversion 

This Appendix illustrates the procedure for converting the 

internal file coordinates of the standard DLG format to the ground 

planimetric UTM reference coordinates. The formulas for this conversion, 

representing a simple offset, rotation, and scale, are as follows: 

X Alx + A2y + A3, and 

Y Aly - A2x + A4, 

where X and Y are the ground planimetric coordinate values and x and y 

are the internal file coordinates. 

The parameters for these formulas (Al, A2, A3, and A4) are contained 

in Header Record B, as double-precision floating-point numbers. 

This example converts four coordinate pairs from internal file 

coordinates to ground planimetric UTM zone 10 coordinate values. The 

parameters are as follows: 

Al =.60959440759 

A2 -.0028817856942 

A3 538248.79341 

A4 4240374.4556 

The internal file coordinates to be converted are as follows: 

X y 

1st pair -8971 -11376 

2nd pair -8955 11375 

3rd pair 8955 11376 

4th pair 8971 -11376 

The calculations to determine the ground planimetric coordinates for 

the first pair are as follows: 

X (0.60959440759) (-8971) + (-0.0028817856942) (-11376) 

+(538248.79341) 

=532 812. 91 

y = (0.60959440759) (-11376) - (-0.0028817856942) (-8~71) 

+(4240374.4556) 

=4 2 3 3 413 • 8 6 

The resulting X,Y coordinate values for the four pairs are as follows: 

X y 

1st pair 532,812.91 4,233,413.86 

2nd pair 532,757.10 4,247,282.79 

3rd pair 543,674.93 4,247,335.01 

4th pair 543,750.25 4,233,465.56 

63 
APPENDIX F.--Sample DLG Data File 

(Standard Distribution Format) 

(Each 144-character record is shown as two consecutive 

72-character lines.) 

GLEN ELLEN 1968 24000 

sw 

3 1 10 -0.122033045000000D 09 0.380180450000000D 08 0.0 

o.o o.o 

o.o 

o.o 

o.o 

o.o 

-0.122625000000000D 03 

0.383750000000000D 02 

-0.122500000000000D 03 

0.609594407590000D 00 

0.424037445560000D 07 

o.o 

o.o 

o.o 

o.o 

o.o o.o 

2 0.610000000000000D 00 0 4 

0.382500000000000D 02 -0.122625000000000D 03 

-0.122500000000000D 03 0.383750000000000D 02 

0.382500000000000D 02 

-0.288178569420000D-02 0.538248793410000D 06 

4 

-89 71-1137 6NW -8955 11375NE 8955 11376SE 8971-11376 

1 

BOUNDARIES (24&25) 795 16 795 7 530 20 

N 1 -89 71-1137 6 0 0 

N 2 -8955 11375 0 0 

N 3 8955 11376 0 0 

N 4 8971-113 76 0 0 

N 5 -8966 3203 0 0 

N 6 2101 11374 0 0 

N 7 5832 11376 0 0 

N 8 7513 11376 0 0 

N 9 8956 7494 0 0 

N 10 8961 2884 0 0 

N 11 3469 10371 0 0 

N 12 5530 9112 0 0 

N 13 -3115-10127 0 0 

N 14 7520 11175 1 0 

90 1 

64 
APPENDIX F.--Sample DLG Data File 

(Standard Distribution Format)--continued 

(Each 144-character record is shown as two consecutive 

72-character lines.) 

N 15 -1450 4596 1 0 

90 1 

N 16 895 4984 1 0 

90 1 

A 1 22 253 1 0 

0 0 

A 2 -4 738 7527 2 0 

91 6 92 97 

A 3 8325 10166 2 0 

91 6 92 97 

A 4 4728 10834 3 0 

91 6 92 97 90 113 

A 5 6463 8917 3 0 

91 6 92 97 90 113 

A 6 161 -1378 3 0 

91 6 92 97 90 113 

A 7 -3058-10280 4 0 

91 6 92 97 90 113 90 130 

L 1 1 5 1 6 2 0 0 

-8971-11376 -8966 3203 

L 2 5 2 1 2 2 0 0 

-8966 3203 -8955 11375 

L 3 2 6 1 2 2 0 0 

-8955 11375 2101 11374 

65 
APPENDIX F.--Sample DLG Data File 

{Standard Distribution Forrnat)--continued 

{Each 144-character record is shown as two consecutive 

72-character lines.) 

L 4 6 7 1 2 4 0 0 

2101 11374 5832 11376 

L 5 7 ~ 1 2 5 2 0 

5832 11376 7513 11376 

L 6 8 3 1 3 2 0 0 

7513 11376 8955 11376 

L 7 3 9 1 3 2 0 0 

8955 11376 8956 7494 

L 8 9 10 1 5 2 0 0 

8956 7494 8961 2884 

L 9 10 4 1 6 2 0 0 

8961 2884 8971-11376 

L 10 4 1 1 6 2 0 0 

8971-11376 -8971-11376 

L 11 13 13 7 6 6 0 0 

-3115-10127 -3189-10286 -2985-10432 -2890-10296 -2943-10236 -3115-10127 

L 12 5 15 2 6 4 2 0 

-8966 3203 -5538 798 -1933 5820 -1450 4596 

99 30 90 203 

L 13 15 16 2 6 2 2 0 

-1450 4596 895 4984 

99 30 90 203 

L 14 14 8 5 3 2 2 0 

7520 11175 7513 11376 

99 30 90 203 

66 
APPENDIX F.--Sample DLG Data File 

(Standard Distribution Format)--continued 

(Each 144-character record is shown as two consecutive 

72-character lines.) 

L 15 14 9 3 5 5 2 0 

7520 11175 7532 10014 7228 9681 7318 8896 8956 7494 

99 30 90 203 

L 16 16 11 2 6 116 2 0 

895 4984 403 5222 275 5186 261 5244 247 5272 188 5344 

166 5364 146 5388 117 5441 107 5501 110 5561 104 5591 

106 5621 122 5681 144 5769 169 5829 199 5882 236 5931 

257 5952 313 5979 336 5999 350 6028 362 6087 362 6147 

352 6208 350 6238 355 6268 372 6295 415 6339 427 6367 

487 6471 496 6500 482 6682 491 6742 496 6803 510 6891 

512 6921 507 6955 507 6984 516 7015 530 7040 553 7062 

629 7111 656 7124 686 7132 741 7160 800 7179 858 7205 

921 7210 982 7223 1011 7236 1026 7261 1068 7309 1119 7386 

1181 7491 1228 7529 1254 7543 1285 7548 1316 7558 1339 7577 

••• etc •••• 

67 
APPENDIX G.--Sample DLG Data File 

(Optional Distribution Format) 

(Each SO-character record is shown as a single line.) 

USGS-NMD DLG DATA - CHARACTER FORMAT - 09-29-82 VERSION 

GLEN ELLEN 1968 24000 

3 1 10 2 0.61000000000D+00 4 

-0.122033045000000D+09 

o.o 

0.380180450000000D+08 

o.o 

o.o o.o 0~0 o.o 

o.o 0.0 

O.lOOOOOOOOOOD+Ol o.o 

sw 38.250000 -122.625000 

NW 38.375000 -122.625000 

NE 38.375000 -122.500000 

SE 38.250000 -122.500000 

BOUNDARIES (24&25) 

N 1 532812.91 

0 16 

4233413.86 

1 -10 

N 2 532757.10 4247282.79 

-2 3 

N 3 543674.93 4247335.01 

-6 7 

N 4 543750.25 4233465.56 

-9 10 

N 5 

-1 

N 6 

-3 

N 7 

-4 

532773.94 4242301.15 

2 12 

539496.77 4247314.04 

4 17 

541771.16 4247326.01 

5 -19 

N 8 542795.89 4247330.85 

-5 6 -14 

N 9 543686.72 4244968.57 

-7 8 -15 

N 10 

-8 

N 11 

-16 

N 12 

-18 

N 13 

11 

N 14 

14 

90 

N 15 

-12 

90 

N 16 

-13 

90 

543703.06 4242158.35 

9 -20 

540333.59 4246706.56 

-17 18 

541593.59 4245945.02 

19 20 

536379.09 4234192.12 

-11 

542800.74 4247208.34 

15 

1 

537351.64 4243171.97 

13 

1 

538780.02 4243415.25 

16 

1 

o.o 

532812.91 

532757.10 

543674.93 

543750.25 

16 010 7 

2 

2 

2 

2 

3 

3 

3 

3 

3 

3 

3 

3 

2 

2 

2 

2 

68 

0 4 

o.o 

o.o 

o.o 

o.o 

o.o 

o.o 

4233413.86 

4247282.79 

4247335.01 

4233465.56 

7 010 20 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

1 0 

1 0 

1 0 

1 

20 1 
APPENDIX G.--Sample DLG Data File 

(Optional Distribution Forrnat)--continued 

(Each SO-character record is shown as a single line.) 

A 1 538261.48 4240528.75 10 0 1 0 0 

-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 

0 0 

A 2 535338.84 4244949.22 6 0 2 0 0 

-12 2 3 17 -16 -13 

91 6 92 97 

A 3 543294.37 4246595.58 4 0 2 0 0 

-15 14 6 7 

91 6 92 97 

A 4 541099.73 4246992.43 4 0 3 0 0 

-17 4 -19 -18 

91 6 92 97 90 113 

A 5 54 2162. 91 4245828.83 6 0 3 0 0 

19 5 -14 15 8 -20 

91 6 92 97 90 113 

A 6 538350.91 4239534.90 10 0 3 0 1 

10 1 12 13 16 18 20 9 0 11 

91 6 92 97 90 113 

A 7 536414.28 4234099.01 1 0 4 0 0 

-11 

91 6 92 97 90 113 90 130 

L 1 1 5 1 6 2 0 0 

532812.91 4233413.86 532773.94 4242301.15 

L 2 5 2 1 2 2 0 0 

532773.94 4242301.15 532757.10 4247282.79 

L 3 2 6 1 2 2 0 0 

532757.10 4247282.79 539496.77 4247314.04 

L 4 6 7 1 4 2 0 0 

539496.77 4247314.04 541771.16 4247326.01 

L 5 7 8 1 5 2 0 0 

541771.16 4247326.01 542795.89 4247330.85 

L 6 8 3 1 3 2 0 0 

542795.8 9 4247330.85 543674.93 4247335.01 

L 7 3 9 1 3 2 0 0 

543674.93 4247335.01 543686.72 4244968.57 

L 8 9 10 1 5 2 0 0 

543686.72 4244968.57 543703.06 4242158.35 

L 9 10 4 1 6 2 0 0 

543703.06 4242158.35 543750.25 4233465.56 

L 10 4 1 1 6 2 0 0 

543750.25 4233465.56 532812.91 4233413.86 

L 11 13 13 7 6 6 0 0 

536379.09 4234192.12 536334.44 4234094.98 536459.22 4234006.56 

536516.74 4234089.74 536484.26 4234126.17 536379.09 4234192.12 

L 12 5 15 2 6 4 2 0 

532773.94 4242301.15 534870.56 4240844.95 537053.68 4243916.72 

5 37351.64 4243171.97 

99 30 90 203 

L 13 15 16 2 6 2 2 0 

537351.64 4243171.97 538780.02 4243415.25 

99 30 90 203 

69 
APPENDIX G.--Sample DLG Data File 

(Optional Distribution Format)--continued 

(Each SO-character record is shown as a single line.) 

L 14 14 8 5 3 2 2 0 

542800.74 4247208.34 542795.89 4247330.85 

99 30 90 203 

L 15 14 9 3 5 5 2 0 

542800.74 4247208.34 542811.40 4246500.64 542627.04 4246296.77 

542684.17 4245818.50 543686.72 4244968.57 

99 30 90 203 

L 16 16 11 2 6 116 2 0 

538780.02 4243415.25 538479.41 4243558.92 538401.49 4243536.60 

538392.79 4243571.92 538384.17 4243588.95 538348.00 4243632.67 

538334.53 4243644.80 538322.27 4243659.37 538304.44 4243691.60 

538298.17 4243728.14 538299.82 4243764.73 538296.08 4243783.00 

538297.21 4243801.29 538306.79 4243837.91 538319.95 4243891.62 

538335.02 4243928.27 538353.15 4243960.66 538375.57 4243990.64 

538388.31 4244003.50 538422.37 4244020.12 538436.33 4244032.38 

538444.78 4244050.10 538451.93 4244086.10 538451.75 4244122.68 

538445.48 4244159.83 538444.17 4244178.11 538447.14 4244196.42 

538457.42 4244212.92 538483.51 4244239.87 538490.74 4244256.97 

538527.02 4244320.54 538532.42 4244338.25 538523.36 4244449.15 

538528.68 4244485.76 538531.55 4244522.96 538539.83 4244576.64 

538540.96 4244594.93 538537.81 4244615.65 538537.73 4244633.32 

538543.13 4244652.25 538551.59 4244667.53 538565.55 4244681.00 

538611.74 4244711.09 538628 .)6 4244719.10 538646.42 4244724.06 

538679.87 4244741.29 538715.78 4244753.04 538751.06 4244769.06 

538789.45 4244772.29 538826.60 4244780.39 538844.24 4244788.39 

538853.31 4244803.68 538878.78 4244833.06 538909.64 4244880.14 

538947.14 4244944.33 538975.68 4244967.63 538991.49 4244976.24 

539010.37 4244979.38 539029.24 4244985.56 539043.21 4244997.21 

•••• etc ••••• 

70 
APPENDIX H.--Quadrangles Digitized Using Pre-1983 

Hydrographic Attribute Codes 

ALABAMA 

Albertville 

Arab 

Bridgeport 

Columbus City 

Flat Rock 

Grant 

Grove Oak 

Guntersville Dam 

Henagar 

Hollywood 

Huntersville 

Langston 

Lim Rock 

Mt. Carmel 

New Home 

Rogersville 

Scottsboro 

Stevenson 

Swearengin 

CALIFORNIA 

Weitchpec 

GEORGIA 

New Home 

ILLINOIS 

Belvidere NE 

Belvidere NW 

Belvidere North 

Belvidere South 

Caledonia 

Capron 

Cherry Valley 

Garden Prairie 

Little Cypress 

Riley 

KANSAS 

Charleston 

Cimarron 

Cimarron NE 

Cimarron NW 

AL 

AL 

AL, TN 

AL 

AL 

AL 

AL 

AL 

AL 

AL 

AL 

AL 

AL 

AL 

AL, TN, GA 

AL 

AL 

AL 

AL 

CA 

AL, TN, GA 

WI I IL 

IL, WI 

IL 

IL 

IL 

IL, WI 

IL 

IL 

IL, KY 

IL 

KS 

KS 

KS 

KS 

71 

Copeland KS 

Copeland NE KS 

Copeland NW KS 

Copeland SE KS 

Dodge City NW KS 

Dodge City SW KS 

Ensign SW KS 

Fowler KS 

Haggard KS 

Horse Thief Canyon sw KS 

Ingalls KS 

Kalvesta KS 

Kalvesta SW KS 

Meade NE KS 

Meade NW KS 

Montezuma KS 

Montezuma NW KS 

Montezuma SE KS 

Pierceville KS 

Pierceville NE KS 

Pierceville SW KS 

Plains NE KS 

Plains NW KS 

Scott City 4 SE KS 

Scott City 4 SW KS 

KENTUCKY 

Briensburg 

Grand Rivers 

Hamlin 

Little Cypress 

Mont 

OREGON 

Acty Mountain 

Acty Mtn. NW 

Adel 

Alger Lake 

Antelope Butte 

Beatys Butte 

Beatys Butte NW 

Blizzard Gap 

Bluejoint Lake East 

Calderwood Reservoir 

Campbell Lake 

Chimney Rock 

Coleman Lake 

KY 

KY 

KY, TN 

IL, KY 

KY 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 
APPENDIX H.--Quadrangles Digitized Using Pre-1983 

Hydrographic Attribute Codes--continued 

OREGON--continued 

Collins Rim 

Coyote Gap 

Coyote Gape SE 

Crane Creek 

Crane Mountain 

Crook Peak 

OR 

OR 

OR 

OR 

OR 

OR 

crooked Creek Valley OR 

crump Lake 

Drake Peak 

Drake Peak NE 

Fish Fin Rim 

Flagstaff Lake 

Flook Lake 

Guano Lake 

Hart Lake 

Hawks Mountain 

Horse Prairie 

Jacobs Reservoir 

Lakeview NE 

Little Honey Creek 

Lone Grave Butte 

Mahogany Butte 

May Lake 

Mud Lake Reservoir 

Murphy Waterholes 

Piute Reservoir 

Plush 

Priday Reservoir 

Rocky Canyon 

Sage Hen Butte 

Sage Hen Flats 

Sixmile Draw 

surveyors Lake 

Swede Knoll 

Valley Falls 

Warner Peak 

TENNESSEE 

Big Spring 

Birchwood 

Bridgeport 

Calhoun 

Charleston 

Daisy 

Fairmount 

Grasshopper Creek 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

OR 

TN 

TN 

AL, TN 

TN 

TN 

TN 

TN 

TN 

72 

Ketner Gap 

New Home 

Ooltewah 

Sequatchie 

Snow Hill 

Soddy 

South Pittsburg 

Ten Mile 

Bangs East 

Bangs West 

Blanket 

Blanket Springs 

Bowser 

Brookesmith 

Brownwood 

Burkett 

Byrds 

Cross Cut 

Democrat 

Elm Grove 

Indian Creek 

Lake Brownwood 

May 

Mercers Gap 

Mercury 

OWens 

Pioneer 

Rising Star 

Sipe Springs 

Star Mountain 

Thrifty 

Trickham 

Zephyr 

VERMONT 

Brandon 

Bread Loaf 

Bristol 

Chittenden 

East Middlebury 

Hancock 

Lincoln 

Mount Carmel 

Mount Ellen 

Pico Peak 

TN 

AL, TN, GA 

TN 

TN 

TN 

TN 

TN 

TN 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

TX 

VT 

VT 

VT 

VT 

VT 

VT 

VT 

VT 

VT 

VT 
APPENDIX H.--Quadrangles Digitized Using Pre-1983 

Hydrographic Attribute Codes--continued 

VERMONT--continued WISCONSIN 

Rochester VT Belvidere NE 

South Mtn. VT Belvidere NW 

Waitsfield VT Capron Warren VT 

73 

WI, IL 

IL, WI 

IL, WI 
....,J 

~ 

DATA CATEGORY 

Rivers and Streams 

APPENDIX I.--Pre-1983 Hydrographic Attribute Codes 

MAJOR MINOR 

TYPE OF CODE APPLICATION CODE CODE 

Feature identification Nodes 030 0001 

0002 

0003 

0004 

0005 

0006 

0007 

0008 

0009 

0010 

0011 

0012 

0013 

0020 

0021 

0022 

0023 

0024 

0025 

0026 

0027 

0028 

0029 

0030 

DESCRIPTION 

River/stream, upper origin 

River/stream, upper origin of stream 

at water body 

River/stream, stream junction 

River/stream, stream intersection with 

bank/shore or estuary 

River/stream, sink (stream goes 

underground or channel is not 

evident) 

River/stream, change in stream 

classification/status 

River/stream, point on stream or 

centerline 

River/stream, stream-canal 

intersection 

River/stream, canal-canal 

intersection 

River/stream, end of canal 

River/stream, canal-shoreline 

interesection 

River/stream, canal over canal 

River/stream, canal over stream 

River/stream, stream road intersection 

River/stream, stream railroad 

intersection 

River/stream, stream trail 

intersection 

River/stream, stream transmission line 

intersection 

River/stream, stream pipeline 

intersection 

River/stream, aqueduct over stream 

River/stream, aqueduct over aqueduct 

River/stream, stream tunnel 

intersection 

River/stream, stream dam intersection 

River/stream, spillway 

River/stream, flood gate or gate 
"""' U'l 

DATA CATEGORY 

Rivers and Streams 

(cont'd.) 

APPENDIX I.--Pre-1983 Hydrographic Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

APPLICATION 

Nodes (cont'd.) 

Areas 

Lines 

MAJOR 

CODE 

030 

000 

030 

MINOR 

CODE 

0031 

0032 

0033 

0034 

0035 

0036 

0037 

0038 

0050 

0051 

0052 

0053 

0054 

0055 

0000 

0226 

0227 

0228 

0229 

0230 

0250 

0251 

0252 

0253 

0254 

0255 

0256 

DESCRIPTION 

River/stream, tide gate 

River/stream, falls 

River/stream, end of rapids 

River/stream, river mile mark 

River/stream, tunnel portal 

River/stream, end of siphon 

River/stream, end of flume 

River/stream, end of penstock 

River/stream, point on bank/shore+ 

River/stream, shore/bank dam 

intersection 

River/stream, gaging station 

River/stream, pumping station 

River/stream, small dam or weir 

River/stream, water intake 

Area outside graph 

River/stream, penstock 

Piver/stream, irrigation ditch 

River/stream, irrigation canal 

River/stream, abandoned canal 

River/stream, canal on levee 

River/stream, right bank, intermittent 

stream 

River/stream, left bank, intermittent 

stream 

River/stream, right bank, perennial 

stream 

River/stream, left bank, perennial 

stream 

River/stream, right bank, braided 

stream 

River/stream, left bank, braided 

stream 

River/stream, right bank, unsurveyed 

stream 
-...! 

m 

DATA CATEGORY 

Rivers and Streams 

(cont'd.) 

APPENDIX r.--Pre-1983 Hydrographic Attribute Codes--continued 

TYPE OF CODE .APPLICATION 

Feature identification Lines (cont'd.) 

Points 

(Degenerate Lines) 

MAJOR MINOR 

CODE 

030 

CODE DESCRIPTION 

0257 River/stream, left bank, unsurveyed 

stream 

0258 River/stream, right bank, sand wash 

0259 River/stream, left bank, sand wash 

OZ60 River/stream, right bank, submerged 

stream 

0261 River/stream, left bank, submerged 

0270 

0271 

0272 

0273 

0274 

0280 

0293 

0294 

stream 

River/stream, shore of island 

River/stream, shore of backwater 

River/stream, bank along levee 

River/stream, apparent shoreline 

(outer limits of vegetation) 

River/stream, shoreline along pier, 

wharf, or jetty 

River/stream, rapids 

River/stream, canal centerline 

extended into lake or pond 

River/stream, stream centerline -

indefinite location 

0295 River/stream, stream centerline 

extended into marsh or swamp 

0296 River/stream, stream centerline 

extended into river 

0297 River/stream, stream centerline 

extended into lake or pond 

0298 River/stream, stream centerline 

extended underground 

0299 River/stream, closing line 

(water-water) 

0350 

0352 

0353 

0354 

Single point feature, river/stream, 

small island or exposed rock 

Single point feature, river/stream, 

spillway 

Single point feature, river/stream, 

flood gate or gate 

Single point feature, river/stream, 

tide gate 
-...1 

-...1 

DATA CATEGORY 

Rivers and Streams 

(cont 'd.) 

water Bodies 

APPENDIX I.--Pre-1983 Hydrographic Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

Parameter 

Feature identification 

APPLICATION 

Points 

(Degenerate Lines) 

(cont'd.) 

Multiple Element 

Types 

Multiple Element 

Types 

Nodes 

MAJOR 

CODE 

030 

030 

03N 

03N 

035 

038 

MINOR 

CODE 

0355 

0356 

0357 

0358 

0000 

0000 

DESCRIPTION 

Single point feature, river/stream, 

river mile mark 

Single point feature, river/stream, 

gaging station 

Single point feature, river/stream, 

pumping station 

Single point feature, river/stream, 

water intake 

Feature added by photorevision methods 

Elevation of water surface (tight 

justified) N=l for feet, N=2 for 

meters, N=6 for feet below datum 

Water depth (right justified) 

N=3 for feet, N=4 for meters 

River mile (right justified) 

Best estimate of classification and/or 

position 

039 00__ Coincident feature or symbol (enter 

040 0001 

0002 

0003 

0004 

0005 

first two digits of major code for 

category of coincident feature in 

blanks, right justified). 

water body, point on shoreline 

water body, shoreline road 

intersection 

water body, shoreline railroad 

intersection 

water body, shoreline transmission 

line intersection 

water body, shoreline pipeline 

intersection 
.....:1 

00 

DATA CATEGORY 

Water Bodies (cont'd.) 

APPENDIX I.--Pre-1983 Hydrographic Attribute Codes--continued 

MAJOR MINOR 

TYPE OF CODE APPLICATION CODE CODE 

Feature identification Areas 000 0000 

040 0100 

0101 

0102 

0103 

0104 

0105 

0106 

0107 

0110 

0111 

0120 

0122 

0123 

0124 

0125 

0126 

0127 

0128 

0129 

0130 

0150 

0199 

0200 

0201 

0202 

0203 

0204 

0205 

0210 

0211 

0299 

DESCRIPTION 

Area outside graph 

Water body, perennial lake or pond 

Water body, perennial salt lake or 

pond 

Water body, intermittent lake or pond 

Water body, intermittent salt lake or 

po~ 

water body, dry lake or pond 

Water body, alkali flat 

Water body, reservoir 

water body, intermittent reservoir 

Water body, glacier or snow field 

Water body, crevasse area 

water body, salt evaporator 

Water body, fish hatchery 

Water body, area subject to controlled 

flooding for agriculture 

water body, industrial water 

impoundment 

water body, area to be submerged 

Water body, fish farm or crawfish farm 

Water body, sewage disposal pond 

water body, large water intake 

Water body, tailings pond 

Water body, wooded lake 

water body, island 

Water body, area not in water body 

Water body, shoreline 

Water body, indefinite shoreline 

Water body, shoreline along wall 

Water body, shoreline along wharf, 

pier, or jetty 

Water body, shoreline along dam 

Water body, shoreline along causeway 

Water body, edge of glacier or 

snowfield 

Water body, edge of crevasse area 

Water body, closure line (water-water) 
-...) 

\0 

DATA CATEGORY 

Water Bodies (cont'd.) 

APPENDIX I.--Pre-1983 Hydrographic Attribute Codes--continued 

TYPE OF CODE 

Feature identification 

Parameter 

APPLICATION 

Lines (cont 'd.) 

Multiple Element 

Types 

Multiple Element 

Types 

MAJOR 

CODE 

040 

040 

04N 

04N 

048 

049 

MINOR 

CODE 

0300 

0301 

0302 

0350 

0351 

0352 

0353 

0354 

0355 

0356 

0000 

0000 

00--

DESCRIPTION 

Single point feature, water body, 

spring 

Single point feature, water body, 

nonflowing well 

Single point feature, water body, 

flowing well 

Single point feature, water body, 

small island or exposed rock 

Single point featrue, water body, 

small perennial pond 

Single point feature, water body, 

small intermittent pond 

Single point feature, water body, 

riser or glory hold 

Single point feature, water body, 

brine or salt well 

Single point feature, water body, 

sulphur well 

Single point feature, water body, 

geyser 

Feature added by photorevision method 

Water surface elevation (right 

justified) N=l for feet, N=2 for 

meters, N=6 for feet below datum 

Water depth (right justified) 

N=3 for feet, N=4 for meters 

Best estimate of classification and/or 

position 

Coincident feature or symbol (enter 

first two digits of major code for 

category of coincident feature in 

blanks, right justified) 




UNITED STATES 

DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY 

RESTON, VIRGINIA 22092 

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OFFICIAL BUSINESS 

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