1866–1868: Red Cloud's War: war against the Lakota Sioux, Cheyenne, and Arapaho Native American groups over control of the Powder River Country and security of the Bozeman Trail in Wyoming and Montana. The allied Indian tribes achieved a victory at the Fetterman Fight and were able to negotiate favorable peace terms in the Treaty of Fort Laramie (1868), which established the Great Sioux Reservation.