USGS 1:100,000 Topographic Quadrangle Series Index U.S.A. 1975-1992
Description
This polygon shapefile represents the geographic extent of USGS 1:100,000 topographic maps (30- by 60-minute quadrangles) for the coterminous U.S. forty-eight states and District of Columbia.
Publisher
Environmental Systems Research Institute (Redlands, Calif.)