Black Hills Corporation, through its subsidiaries, operates as an electric and natural gas utility company in the United States. It operates in two segments, Electric Utilities and Gas Utilities. The Electric Utilities segment generates, transmits, and distributes electricity to approximately 218,000 electric utility customers in Colorado, Montana, South Dakota, and Wyoming; and owns and operates 1,481.5 megawatts of generation capacity and 8,892 miles of electric transmission and distribution lines.