provoked by a treaty-violating ultimatum to surrender their sacred Black Hills (Paha Sapa), where an expedition under Custer discovered gold in 1874. In June 1876, driven by converging army columns, a unique concentration of Sioux and Cheyenne/Arapaho in southern Montana first repulsed a 1, 000-man column under Crook at the Rosebud and then destroyed Custer's command at Little Bighorn.