The first U.S. Government sponsored expedition to enter Jackson Hole was the 1859-60 Raynolds Expedition. Led by U.S. Army Captain William F. Raynolds and guided by mountain man Jim Bridger, it included naturalist F. V. Hayden, who later led other expeditions to the region. The expedition had been charged with exploring the Yellowstone region, but encountered difficulties crossing mountain passes due to snow. Bridger ended up guiding the expedition south over Union Pass then following the Gros Ventre River drainage to the Snake River and leaving the region over Teton Pass. Organized exploration of the region was halted during the American Civil War but resumed when F. V. Hayden led the well-funded Hayden Geological Survey of 1871. In 1872, Hayden oversaw explorations in Yellowstone, while a branch of his expedition known as the Snake River Division was led by James Stevenson and explored the Teton region. Along with Stevenson was photographer William Henry Jackson who took the first photographs of the Teton Range. The Hayden Geological Survey named many of the mountains and lakes in the region. The explorations by early mountain men and subsequent expeditions failed to identify any sources of economically viable mineral wealth. Nevertheless, small groups of prospectors set up claims and mining operations on several of the creeks and rivers. By 1900 all organized efforts to retrieve minerals had been abandoned.