Coutersy: www.eia.gov

Surface mines (sometimes called strip mines) were the source of about 64% of the coal mined in the United States in 2020. These mining operations remove the soil and rock above coal deposits, or seams. The largest surface mines in the United States are in Wyoming’s Powder River Basin, where coal deposits are close to the surface and are up to 70 feet thick.

Mountaintop removal and valley fill mining has affected large areas of the Appalachian Mountains in West Virginia and Kentucky. In this form of coal extraction, the tops of mountains are removed using explosives. This technique changes the landscape, and streams are sometimes covered with rock and dirt. The water draining from these filled valleys may contain pollutants that can harm aquatic wildlife downstream. Although mountaintop mining has existed since the 1970s, its use became more widespread and controversial beginning in the 1990s.

U.S. laws require that dust and water runoff from areas affected by coal mining operations must be controlled, and the area must be reclaimed close to its original condition.