A topographic map shows human and physical features of the Earth and can be distinguished from other maps by its great detail and by its contour lines indicating elevation. Topographic maps are excellent sources of detailed information about a very small area of the Earth. The United States Geological Survey (USGS) produces a set of topographic maps for the United States that are at a scale of 1:24,000 (one inch equaling 2,000 feet [or 1 centimeter equaling about 240 kilometers]). You can purchase these maps online, at sporting goods stores, or through the USGS itself.