NorthWestern Corporation provides electricity and natural gas services in the Upper Midwest and Northwest of the U.S. in the states of Montana, South Dakota, and Nebraska. The primary segments of the company include Electric operations, which operates only in Montana and South Dakota, and Natural Gas operations, which operates in all three states. The company uses thermal, wind, hydro, or renewable energy in varying quantities, depending on the location of the facilities, in order to generate power. The company derives the majority of retail electric utility revenue from commercial and residential sales.