This document defines a U.S. Geological Survey (USGS) digital topographic map. This map series, named “US Topo,” is modeled on what is referred to as the standard USGS 7.5-minute (1:24,000-scale) topographic map series that was created during the period from 1947 to approximately 1992. The US Topo map product has the same extent, scale, and general layout as the older standard topographic maps. However, unlike the previous maps, US Topo maps are published using Adobe Systems Inc. Portable Document Format (PDF) with a geospatial extension that is called Georeferenced PDF (GeoPDF), patented by TerraGo Technologies. In addition, the US Topo map products incorporate an orthorectified image along with data that was included in the standard 7.5-minute topographic maps. US Topo maps are intended to serve conventional map users by providing Geographic Information System (GIS) information in symbolized form in the customary topographic map layout. The maps are not intended for GIS analysis applications. Read More