Red Cloud (1822-1909), chief of the Oglala Sioux, who, for a time, successfully resisted United States occupation of what are now parts of Wyoming, Montana, and South Dakota. During the 1860s, Red Cloud fought to keep the U.S. Army from opening the Bozeman Trail, which led to the Montana gold fields through an important Sioux hunting area. In 1866 Red Cloud assumed leadership of a group of Sioux and Cheyenne that opposed the army's plans to build three fortifications to keep the trail open. For two years Red Cloud and his allies besieged these forts. Finally in 1868 the U.S. government agreed to abandon its efforts and to burn the three forts. Red Cloud signed the 1868 Treaty of Fort Laramie on April 29, 1869. The U.S. government, however, tricked Red Cloud; although it agreed to abandon the Bozeman Trail, the treaty included a provision that relocated the Sioux to a reservation in present-day South Dakota. In 1874 George Armstrong Custer led mining experts on an expedition into the Black Hills and discovered gold; people poured into the area. The Sioux felt betrayed by this violation of their sacred hills, and the Sioux War of 1875-1876 began. Red Cloud did not support the radical leader, Crazy Horse, but he was not willing to sacrifice the Black Hills. Because of superior resources and weapons, the U.S. Army defeated the Sioux and forced them onto reservations. Red Cloud was removed as Oglala chief after a dispute with a government agent in 1881, and he spent his last years at Pine Ridge Reservation in South Dakota.