Established January 8, 1881 with its county seat at Challis. Named for the General Custer mine, which was named in honor of General George Custer who died at the Battle of Little Bighorn. Its history begins with fur traders and pathfinders as early as 1824; later in the 1860s and 1870s prospectors and miners came. It contains portions of the Sawtooth, Salmon River, White Cloud, Pioneer, Lost River, and White Knob Mountains and contains the highest peaks in the state.