20220712 08053700 1.0 TRUE 100K_QUAD_INDEX This polygon shapefile provides an index grid based on latitude and longitude intervals corresponding to the USGS topographic quadrangle series at 1:100,000 scale. The latitude/longitude interval corresponding to this quadrangle index is 30 minutes latitude by 60 minutes longitude. Attributes include Quad Name, Quad Publication Year, and 100K DRG Name. US Geological Survey