USGS Professional Paper 1809: Coal Geology and Assessment of Coal .
WEBMay 12, 2015 · The basin covers about 19,500 square miles, exclusive of the part of the basin within the Crow and Northern Cheyenne Indian Reservations in Montana. The Powder River Basin, which contains the largest resources of lowsulfur, lowash, subbituminous coal in the United States, is the single most important coal basin in the .