NorthWestern Energy Group, Inc. provides electricity and natural gas to residential, commercial, and various industrial customers. It generates, purchases, transmits, and distributes electricity; and ... NorthWestern Energy Group, Inc. provides electricity and natural gas to residential, commercial, and various industrial customers. It generates, purchases, transmits, and distributes electricity; and produces, purchases, stores, transmits, and distributes natural gas, as well as owns municipal franchises to provide natural gas service in the communities. The company operates 6,600 miles of electric transmission and 18,674 miles of electric distribution lines with approximately 395 transmission and distribution substations; and 2,235 miles of natural gas transmission and 5,155 miles of natural gas distribution lines with approximately 133 city gate stations in Montana. It also operates 1,310 miles of electric transmission and 2,365 miles of electric distribution lines in South Dakota with approximately 124 transmission and distribution substations; and 55 miles of natural gas transmission and 2,573 miles of natural gas distribution lines in South Dakota and Nebraska. The company provides electricity and/or natural gas to approximately 775,300 customers in Montana, South Dakota, Nebraska, and Yellowstone National Park. NorthWestern Energy Group, Inc. was founded in 1923 and is based in Sioux Falls, South Dakota.