This polygon shapefile represents the geographic extent of USGS 1:24,000 topographic maps (7.5- by 7.5-minute quadrangles) for the coterminous U.S. forty-eight states and District of Columbia. This layer is part of the 2014 ESRI Data and Maps collection for ArcGIS 10.2.U.S. USGS 1:24,000 Topographic Quadrangle Series Index provides quadrangle name, identification number, publication data, and map coverage by state for each quadrangle. This large-scale index grid is appropriate for display at more detailed scales.