NorthWestern Corp. engages in generating and distributing electricity and natural gas. It operates through the following segments: Electric Utility Operations, Natural Gas Operations, and All Other. The Electric Utility Operations segment includes generation, transmission, and distribution of electric utility business as a vertically integrated generation transmission and distribution utility. The Natural Gas Operations segment comprises production, storage, transmission, and distribution of natural gas. The All Other segment consists of unallocated corporate costs. The company was founded in November 1923 and is headquartered in Sioux Falls, SD.