Tri-State Generation and Transmission Association

Tri-State Generation and Transmission Association is a nonprofit cooperative based in Colorado. It supplies power to 43 electric cooperatives across four states. Tri-State serves over one million consumers across nearly 200,000 square miles. Its energy mix includes coal, natural gas, hydro, wind, and solar. The cooperative operates more than 5,700 miles of transmission lines. Tri-State emphasizes reliable, affordable electricity and environmental stewardship. It was among the first cooperatives to adopt a formal environmental management system.