Upper Missouri was organized in 1957 to serve transmission needs of rural electric cooperatives in eastern Montana and western North Dakota. Upper Missouri provides service to 11 electric distribution cooperatives, 6 in eastern Montana and 5 in western North Dakota. The 11 member systems serve 76,658 meters to farms, ranches, homes, and businesses in 37 counties, representing over 54,762 square miles.

Upper Missouri sources power from two major suppliers, Western Area Power Administration and Basin Electric Power Cooperative. 96.2% of the power is sourced from Basin.

Upper Missouri has seen dramatic energy sales and demand growth, now a 1,366 MW system. Upper Missouri is projected to need another 288 MW of capacity in the next 20 years.

The headquarters facility for Upper Missouri is located in Sidney, Montana which is the county seat of Richland County. Sidney is also a major shopping center in Eastern Montana. Its exceptional medical facilities add to the areas status as a major retail center.  The area ranks at or near the top of all Montana counties in a number of agriculture and other production areas. It ranks second in oil production in the state and its livestock center is ranked sixth. The area has one of the lowest unemployment rates in the nation due to the current surge in crude-oil production as companies scramble to attract workers to keep pace with the oil production. The area also offers great recreational opportunities to relax in the “great outdoors” with many activities such as hunting, fishing, camping, hiking, golf, and boating.