NorthWestern Corp. engages in generating and distributing electricity and natural gas. It operates through the following segments: Electric Operations, Natural Gas Operations, and All Other. The Electric Operations segment includes generation, transmission, and distribution of electric utility business as a vertically integrated generation transmission and distribution utility in Montana and South Dakota. The Natural Gas Operations segment includes the 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.