Topographic maps, or topos, show natural features as well as cultural features, such as buildings. These maps use contours to depict the shape and elevation of terrain.
Topos can be used for a variety of purposes, including but not limited to: engineering, recreational purposes, land management, and planning.
The U.S. Geological Survey (USGS) has been making topographic maps for over 125 years.
Other agencies develop their own maps derived from USGS topos. Information about the Bureau of Land Management (BLM) Surface Management Maps and the U.S. Forest Service FSTopo maps can be found under the Public Lands tab.
USGS topographic maps come in a variety of scales. The most popular and the most detailed are the 7.5-minute or 1:24,000-scale (1 inch = 2,000 feet) quadrangle series. Depending on latitude, the area portrayed by the 7.5-minute series ranges from 49 to 64 square miles. It takes about 57,000 7.5-minute maps to cover the 48 contiguous states.
Next are the 15-minute or 1:62,500-scale. The full coverage of this series has been discontinued, but remains the standard map series covering Alaska. The 15-minute series of the lower 48 states has been replaced by the 7.5-minute series.
Nearly all of the contiguous 48 states and Hawaii are covered by the 1:100,000-scale (1 centimeter = 1 kilometer) series of topographic maps. For the most part they are derived from the 1:24,000-scale series.
Other series include the County Map series, 1:250,000-scale series, State Map series, National Park map series, Shaded-relief maps, Topographic-bathymetric maps, and Antarctic maps.
The USGS no longer produces print topos, but there are a variety of ways to access USGS topos online for free. The most common point of access involves locating the area of interest on the map, then selecting and downloading the file(s).
USGS has two digital collections of maps: US Topo and the Historical Topographic Map Collection (HTMC). All topos are available as downloadable georeferenced PDF files. US Topo maps have been published digitally since 2009 as layered PDFs with both vector and raster data. The HTMC maps date from 1882 through 2006. The files are not small—for example, the median file size for US Topo is 22MB.
More information about using these files and the HTMC is available in the quickstart guide, US Topo Map and Historical Topographic Map Users Guide.