Black Hills Corporation is a US electric and natural gas utility holding company operating through Electric Utilities and Gas Utilities segments. The Electric Utilities segment generates, transmits, and distributes electricity in Colorado, Montana, South Dakota, and Wyoming, with 1,386 MW of generation capacity and 9,478 miles of transmission and distribution lines, and also sells excess power and owns non-regulated generation and mining assets. The Gas Utilities segment distributes natural gas to about 1,138,000 customers in Arkansas, Colorado, Iowa, Kansas, Nebraska, and Wyoming, and operates 4,581 miles of intrastate transmission pipelines, 44,840 miles of distribution mains and service lines, seven storage sites, and about 50,000 horsepower of compression and 494 miles of gathering lines. The company also offers non-regulated services such as Service Guard Comfort Plan, Tech Services, and HomeServe, and produces power from wind, natural gas, and coal-fired plants, as well as coal from a mine near Gillette, Wyoming. Incorporated in 1941, it is headquartered in Rapid City, South Dakota.