Powder River Basin Coal Field

In the Powder River Basin coal field – the most prolific in the world – coal is mined from two major coal seams, the Anderson and Canyon coals. This coal occurs in the Paleocene-age (65 to 55 million years ago) Tongue River Member of the Fort Union Formation. The mineable subbituminous coal seams in the Fort Union Formation are 60 to 80 feet thick, with a moisture content between 20 and 30 percent, and contain less than 6 percent ash and 0.5 percent sulfur. Powder River coal also extends into the Eocene-age Wasatch Formation, and exploration drilling has encountered coal seams greater than 200 feet thick.
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The Wyoming State Geological Survey is a major source of information on Wyoming’s coal and production efforts. Our coal geologists work to study, examine, and provide knowledge on coal geology and coal resources. We prepare and publish reports and maps, as well as develop educational products for the public.


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Chris Carroll
Chris Carroll
(307) 766-2286 Ext. 243