NorthWestern Energy Group Inc provides electricity and natural gas services in the Upper Midwest and Northwest of the U.S. in the states of Montana, South Dakota, Nebraska, and Yellowstone National Park. The company's primary segments include Electric utility operations, which include the generation, purchase, transmission, and distribution of electricity, and Natural Gas utility operations, which include the production, purchase, transmission, storage, and distribution of natural gas. The company uses thermal, wind, hydro, or renewable energy in varying quantities, depending on the location of the facilities, to generate power. The company derives the majority of revenue from Electric utility operations segment.