A worker stands inside an idle bucket that can hold 170 cubic yards of material while unearthing rock in a coal seam. Arch Coal employs over 500 workers at the Black Thunder Mine, which for many years was the nation’s single largest coalmine in Wyoming’s Powder River Basin.
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 the company web site, the mine surpassed a 750 million ton shipment milestone 25 years after opening in 1977.