Wild Lands of the West | The BLM, National Geographic Magazine: Inside Black Thunder Coal Mine

Coal falls from a bucket as material is loaded from a pit into trucks in a large mine.

The Black Thunder Coal Mine in Wyoming’s Powder River Basin is the largest surface coal mine in the country. The dragline uncovers the earth down to a coal seam with a bucket that holds 170 cubic yards of rock.

Trucks are filled with coal which is then transferred to trains that haul it to power plants in tMissouri, Illinois and Tennessee. Approximately 91 tons of low sulpher coal is extracted from the mine annually.

The Arch Coal Company employs over 500 workers at Black Thunder, which is regulated by the Bureau of Land Management and for many years was the nation’s single largest coal mine.

Five draglines work the 70-foot Wyodak seam, producing more than 65 million tons of coal annually on federal land. Once the low-sulfur, sub-bituminous coal is crushed it is suitable for power station fuel without any other preparation.

The Black Thunder Mine produces more than two tons of coal per second, 24 hours a day, 365 days a year. According to Arch Coal Company, the mine surpassed a 750 million ton shipment milestone 25 years after opening in 1977.