NorthWestern Corporation, d/b/a NorthWestern Energy, is an investor-owned utility and one of the largest providers of electricity and natural gas in the northern tier states. We serve approximately 775,500 customers in Montana, South Dakota and Nebraska. Classified as a “mid-sized” utility by most industry standards, our service territory size is one of the largest in the country. The foundation of NorthWestern’s energy business dates back to 1923, with the start of the utility operations in a few communities in South Dakota and Nebraska. Our electric system serves 337 communities and surrounding rural areas covering two-thirds of Montana, eastern South Dakota, and Yellowstone National Park in Wyoming. Our natural gas system serves 202 communities and surrounding rural areas in Montana, South Dakota and central Nebraska. NorthWestern Energy has approximately 1,600 full-time employees. Our corporate headquarters is in Sioux Falls, South Dakota, with operational headquarters in Butte, Montana, and Huron, South Dakota. We are listed on the New York Stock Exchange under the ticker symbol NWE.