This polygon shapefile shows the coal fields of Alaska and the conterminous United States. Most of the material for the conterminous United States was collected from James Trumbull's "Coal Fields of the United States, Conterminous United States" map (sheet 1, 1960). The Gulf Coast region was updated using generalized, coal-bearing geology obtained from State geologic maps. The Alaska coal fields were collected from Farrell Barnes's "Coal Fields of the United States, Alaska" map (sheet 2, 1961). This layer is part of the 1997-2014 edition National Atlas of the United States.These data are intended for geographic display and analysis at the National level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:5,000,000-scale data. No responsibility is assumed by the U.S. Geological Survey or the National Atlas of the United States in the use of these data.