MDU Resources Group, Inc. operates regulated energy delivery businesses in the United States through three segments: Electric, Natural Gas Distribution, and Pipeline. It generates, transmits, and distributes electricity in Montana, North Dakota, South Dakota, and Wyoming using about 3,400 miles of transmission lines, 4,900 miles of distribution lines, 86 transmission substations, and 299 distribution substations. The company distributes natural gas in Idaho, Minnesota, Montana, North Dakota, Oregon, South Dakota, Washington, and Wyoming through roughly 22,000 miles of distribution and 540 miles of transmission systems, and supplies related value-added services. It also provides natural gas transportation and underground storage through a regulated pipeline system mainly in the Rocky Mountain and northern Great Plains regions, along with cathodic protection non-regulated energy-related services. Incorporated in 1924, MDU Resources Group, Inc. is headquartered in Bismarck, North Dakota.