Caribou Mountain rises 9,800 feet, with alpine snowfields feeding Tincup Creek, a tributary of the South Fork of the Snake River. Placer gold discoveries high on the mountain in 1871 led to a gold rush that lasted for two decades. In the 1880s, sheep and cattle herds moved back and forth in Tincup Creek to graze on summer pasture, an activity that still occurs. The origin of the name Tincup Creek is uncertain; one story holds that a young girl was kidnapped by Indians and the only thing wanted in trade back to her parents was a tin cup. The 1.1 million-acre Caribou National Forest was created in 1907 when President Theodore Roosevelt established the national forest system and set aside several million acres of western public domain land as forest reserves. These lands were left as a legacy for future generations to use and enjoy, providing a sustainable supply of timber, water, grazing, wildlife, fisheries, minerals, and outdoor recreation. Early forest service efforts reduced forest and range fires, improved range conditions, supported sustainable timber harvest, and opened access to the national forests for the public. In the 1930s, the Civilian Conservation Corps, formed to relieve the effects of the Great Depression, built many improvements on the national forests, including Tincup and Pine Bar campgrounds in Tincup Canyon. Numerous forest service trailheads are located in Tincup Canyon, including access to the South Fork of Tincup Creek and the Tincup Mountain trails. The area also contains twisted and faulted Mesozoic sandstone and shale deposits laid down between 260 and 65 million years ago and deformed as part of the Idaho-Wyoming thrust belt, and Cretaceous dinosaur fossils are found in the Wayan Formation.