TopoViewTopoView highlights one of the USGS's most important and useful products, the topographic map. In 1879, the USGS began to map the Nation's topography. This mapping was done at different levels of detail, in order to support various land use and other purposes. As the years passed, the USGS produced new map versions of each area. The most current map of each area is available from The National Map. TopoView shows the many and varied older maps of each area, and so is especially useful for historical purposes—for example, the names of some natural and cultural features have changed over time, and the historical names can be found on many of these topographic maps.
