This layer presents the geographic extent of USGS 1:24,000 topographic maps for the conterminous U.S. forty-eight states and District of Columbia. It provides quadrangle name, identification number, publication data, and map coverage by state for each quadrangle. This large-scale index grid can be a handy visual reference for regional displays. These data are a subset of a larger dataset published by the organization listed in the credits. Great Smoky Mountains National Park makes these data available in this form such that users can: effectively manipulate data for park mapping activities that do not require the acquisition of a large, nation-wide data set; alter symbology and rendering parameters natively; restrict analysis of geospatial data to an extent that coincides with the park footprint.