This is a coverage of surface and Federal mineral ownership in the Powder River Basin area, Montana and Wyoming. This coverage is the combination of several ARC/INFO coverages and MOSS format files that were collected from the BLM, reformatted as needed, modified, and/or created by the USGS from hard copy BLM 1:100,000-scale surface and mineral management status maps. The Powder River Basin has the largest in-place coal resources of any field in the contiguous U.S. (Keystone, 1997), and produces over one-fourth of the Nation's total coal production (The Mining Record, 1997). In the Powder River Basin, very little of the surface is Federal land, yet almost all of the coal is Federally owned.