Building on the success from more than 132 years mapping the Nation, US Topo maps are georeferenced digital maps produced from the data of The National Map. The quadrangles are designed to be used like the traditional 7.5-minute paper topographic maps for which the USGS is so well known. However, in contrast to paper-based maps, US Topo maps provide modern technical advantages that support faster, wider public distribution, basic, on-screen geographic analysis and local printing options for all users.
The maps are published in Portable Document Format (PDF) using a georeferencing mechanism that is ISO 32000 compliant. They can be viewed and printed with Adobe Reader or comparable PDF viewing software. The geospatial PDF maps provide limited GIS functionality, such as displaying ground coordinates and measuring distances and areas. Layered PDF files allow users to turn data layers on and off. Freely available for download from the USGS Store and The National Map download client, the maps are constructed using key layers of geospatial data from the National Map databases.