The early phases of the US Topo program are discussed in a May, 2011 paper [http://www.directionsmag.com/articles/us-topo-a-new-national-map-series/178707]. In September, 2012, the first three-year production cycle was completed and nearly full coverage of the conterminous United States with a new national map series was achieved.
Mass Production of Contour Maps
The primary strategic goal of the US Topo program is to refresh the national map series for all U.S. states and territories on a regular three-year cycle. For the conterminous 48 states alone, this requires publishing 18,000 maps per year or 72 maps every work day. This production goal has been met for three consecutive years, and between late 2009 and late 2012, the conterminous 48 states were completely covered with new topographic maps.
Maps created in early 2009 were simple image maps without contours or hydrography. These were named “Digital Map – Beta” and are now regarded as experimental and temporary. These maps were removed from public view as they were replaced with contour maps in 2012. In future three year cycles, the older maps will be retained as historical data and will continue to be available for download. The second three year cycle of US Topo production began in October, 2012.
US Topo maps are distributed through an http download service. The USGS maintains two interfaces to this service, the “Map Locator and Downloader” application at http://store.usgs.gov, and The National Map Viewer at http://viewer.nationalmap.gov/viewer/.
US Topo downloads from USGS Store: