The Geographic Names Information System (GNIS) contains name and locative information about almost 2 million physical and cultural features located throughout the United States and its Territories. GNIS was developed by the U.S. Geological Survey in cooperation with the U.S. Board on Geographic Names (BGN) to promote the standardization of feature names. GNIS is being compiled in phases. The first phase is complete for the entire U.S., and entailed the collection of names from Federal sources including large-scale USGS topographic maps, National Ocean Service charts, U.S. Forest Service maps, and digital datasets distributed by the Federal Communications Commission, the Federal Aviation Administration, and the U.S. Army Corps of Engineers. The second phase of data collection is complete or in progress for about 65% of the U.S., and captures names from State, locally, and privately published current and historical maps, charts, and texts.
The USGS distributes standard-format digital extracts from GNIS that contain information about features in each State and Territory. Two thematic extracts are also available. The Populated Places file lists information about all cities and towns throughout the U.S. that are described in the database. The U.S. Concise file lists information about large physical and cultural features.
The data available from this system is not in a GIS format; information is downloaded as an ASCII file, with fixed field lengths. One of the fields does contain Latitude and Longitude coordinates, and that information can be used to create a point coverage showing the locations of the places. Specific information on these fields can be found in the data sources and data tools sections below.
GNIS Data Sources and Tools for Using GNIS Data
Main GNIS site for downloading data and
performing on-line queries of the database. There is also considerable documentation at
this site. The on-line queries give you considerable information about various sites in
the database, but you will likely wish to download the datafiles if you need to use the
data to create GIS coverages.
Specific information on file sizes, status, and digital file formats can be
found in the GNIS datasets via Anonymous FTP section of the GNIS site.
An edited copy (field length information has been added) of the readme file
from that section is included here for your information.
Note on importing ASCII files into a database - The data files are compressed
with the GZip utility, and need to be uncompressed before using. They also need to be run
through the "chop" utility or other equivalent utility to put a PC end of line
marker in the file at the correct point, as they appear to be UNIX files. See the UNIX to DOS note for further details on how to use GZip and Chop.
The documentation on the ASCII fixed field files for the state-wide coverages (readme
file) indicates that the total row length for the data is 235 characters. For at least
some of the files this is not correct; the rows were 239 characters long. The difference
was in the length of the last field. To get the data to import correctly, the chop utility
was used to put the end-of-row marker at 239 characters (chop 239 <oldfile>
newfile). You may need to check any files you download if you have trouble importing them
into a database and confirm the row length. The Delaware file could be opened with a text
editor to check row length, but that was a small file.
GNIS Data User's Guide in Word format, zipped with PKZip. This document was retrieved from the USGS site (USGS Gazetteer Download Site) and is the most current available, but the document does state that it is still officially a draft. The Gazetteer site can be checked if you wish to see about any updated documentation.
For additional information regarding this Web page, contact Deb Southworth Green , in the Division of Information Resources and Technology Management, at Deb_Green@fws.gov
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Last Modified January 03, 2001 10:32 AM