Geological Survey (U.S.)

The United States Geological Survey (USGS) was created by Act of Congress on March 3, 1879 and charged with the "classification of the public lands, and the examination of the geological structure, mineral resources, and products of the national domain." Over the years, the USGS has issued many maps documenting the physical geography of the country, often in great detail. In recent years, the USGS has focused on providing information about ecosystems and the environment.