Massive machinery at work in the open-pit Wyodak coal mine in the coal-rich Powder River Basin outside Gillette, Wyoming
. The operation utilizes a truck and shovel mining method to produce a low-sulfur, sub-bituminous coal that is used for domestic energy generation. The mine ships its coal to the adjacent Wyodak power plant and to other customers via railroad. The mine is operated by Wyodak Resources Development, a subsidiary of the Black Hills Corporation. Photo by Carol Highsmith.