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. ESRI and U.S. Geological Survey. (2014). USGS 1:24,000 Topographic Quadrangle Series Index, 2010. ESRI. Available at: http://purl.stanford.edu/fs905pm3380