Topographic maps use contour lines to show the shape of the earth's surface.
The United States Geological Survey began mapping the country in 1879 and has been the primary civilian mapping agency of the United States ever since. The best known USGS maps are the 1:24,000-scale topographic maps, also known as 7.5-minute quadrangles. In addition to elevation, they show such features as streets, buildings, streams, and woods. This is the only uniform map series that covers the entire area of the United States in considerable detail.
The 7.5-minute map series was officially completed in 1992, and in 2001 the program was replaced by The National Map, which is a nationwide collection of integrated data from local, State, Federal, and other sources.
The UNT Libraries' Government Documents Department has 7.5-minute topographic maps in hardcopy for most of Texas, as well as for Oklahoma, Louisiana, Arkansas, and New Mexico. If you would like to see a topographic map for a particular area, ask for the map by quadrangle name at the Government Documents Service Desk.
To obtain free map indexes and catalogs, and to order topographic maps or any of the wide variety of thematic maps available from the USGS, contact:
USGS Information Services
Denver CO 80225
1-888-ASK-USGS or 303-202-4700
Web site: Ask USGS
Visit the USGS home page at www.usgs.gov/