What is the biggest coal deposit in the United States?

The biggest coal deposit by volume is the Powder River Basin in Wyoming and Montana, which the USGS estimated to have 1.07 trillion short tons of in-place coal resources, 162 billion short tons of recoverable coal resources, and 25 billion short tons of economic coal resources (also called reserves) in 2013. The coal in the Powder River Basin is subbituminous in rank. Large coal deposits can also be found in the Williston Basin in North Dakota and Montana (lignite in rank), the Appalachian Basin in Ohio, Pennsylvania, West Virginia, Virginia, and Alabama (bituminous in rank), and the Illinois Basin in Illinois and Indiana (bituminous in rank).

Learn more: U.S. Coal Resources and Assessment