NorthWestern Corporation, doing business as North-Western Energy, provides electricity and natural gas. The Company provides electricity and natural gas to over 701,000 customers in Montana, South Dakota and Nebraska. It generates and distributes electricity in South Dakota; distributes natural gas in South Dakota and Nebraska, and generates and distributes electricity and distributed natural gas in Montana. The Company's segments are Electric operations, Natural gas operations and All other, which primarily consists of unallocated corporate costs. The Company's regulated electric utility business in Montana includes generation, transmission and distribution. Its service territory covers approximately 107,600 square miles, representing over 73% of Montana's land area. Its regulated natural gas utility business in Montana includes production, storage, transmission and distribution. The Company distributes natural gas to approximately 191,500 customers in over 105 Montana communities.