The rural electrification program was launched in 1935 to help rural Americans obtain central station electric service in the only way it was economically feasible for them to do so - by pooling their resources. Farmers, ranchers and rural people from all walks of life joined together, took advantage of government loan programs and formed consumer-owned REC’s Finally, after years of hearing it couldn't be done, the lights began coming on in the American countryside. Fifteen years later Rushmore Electric Power Cooperative was organized to give the rural electric cooperative consumers of western South Dakota something else they desperately needed but couldn't obtain in any other fashion - their own power generation and transmission system. This time, however, it wasn't simply a group of farmers and ranchers pooling their resources, but a group of the rural electric distribution cooperatives they owned.

Prior to 1950, South Dakota's REC’s were able to purchase all the power they needed from privately owned utilities. However, by the early 1950’s it was becoming clear that the demand for power in the countryside would soon outgrow the supply. Suddenly the cooperatives had a major dilemma on their hands. Where were they going to purchase power when the private power companies were no longer able to fill their member's needs? The Federal Flood Control Act of 1944 had promised to provide REC’s with a large future supply of electricity by authorizing the construction of dams along the Missouri River. Unfortunately, in 1950 an adequate supply of power from those dams was still more than a decade away. For the rural people of western South Dakota the answer would once again be self-reliance. After much debate, a group of five west river REC’s (Black Hills Electric, Butte Electric, Lacreek Electric, West Central Electric and West River Electric) determined that their only viable option was to generate their own power to meet current demands, and expand their transmission system in anticipation of receiving federal hydro power. Rushmore Electric Power Cooperative was born. By pooling their resources in Rushmore, those five cooperatives began a partnership which has secured an adequate supply of reasonably priced electricity for the rural residents of western and central South Dakota for more than 50 years. What follows is a chronological history of Rushmore's success and growth: 1950 Rushmore is incorporated, 1952 Rushmore contracts with Black Hills Power and Light to build a generating unit at their Osage, WY plant, June 1952 Rushmore's 10,000 KW Osage unit comes on line, 1955 Tri -County Electric Association joins Rushmore bringing over 2,000 new consumers, 1955 Rushmore contracts with BHP&L again to build an additional 16,500 KW generating unit at their Kirk plant near Lead, South Dakota, 1954 the Hydro-electric generating plant at Ft. Randall Dam comes on line followed by Gavin's Point ('56), Oahe ('62) and Big Bend ('64). Federal hydro-power, marketed through the Western Area Power Administration, then provided 100% of Rushmore's requirements, 1961 eight Missouri Basin states join forces to form a regional G&T, Basin Electric Power Cooperative, 1965 Basin begins generating power from its first plant, Leland Olds Station, to meet the supplemental power requirements of its members. Between 1972 and 1984 three more cooperatives, Cam Wal ('72), Cherry- Todd ('80) and Moreau-Grand ('84), join Rushmore. 1988 Tri-County Electric leaves Rushmore to become a Class A member of Basin. In 1994 Rushmore sold both its Osage and Kirk generating units. In 2012, Rushmore purchased roughly 84% of its power from Basin and 16% from the Federal Hydro- Electric System.

Eight member systems; Serving over 57,102 consumers in western and central South Dakota; Annual electric sales of 1,218,697 MWH.