E. Lynn Usery 2019 <p>The U.S. Geological Survey (USGS), the United States' official national topographic mapping organization, is building and maintaining geographic databases for fundamental base geographic layers of land cover, structures, boundaries, hydrography, geographic names, transportation, elevation, and orthoimagery as The National Map. Data from the 3D Elevation Program, the National Hydrography Dataset and other national programs provide public domain, authoritative, accurate, and reliable data for The National Map, and data are served to United States government organizations and the public. Products of The National Map include viewable and downloadable data for all data layers, derivative products including US Topo, and web services of the data. The US Topo product is automatically generated from national map databases and produces topographic maps every three years for all 48 of the contiguous United States, Hawaii, and the United States territories.</p> application/pdf en Cartography and Geographic Information Society U.S. Geological Survey accomplishments in cartography 2015-2019 text