The discovery of gold in Montana in 1862 created a rush of miners traveling to Virginia city. The most direct routes were through Wyoming on the Bridger and Bozeman trails. In the spring of 1863, John Bozeman, a miner from Georgia, pioneered a route leaving the Oregon/California/Mormon Trail near Fort Fetterman and traveled east of the Big Horn Mountains through the Powder River Country. This area was hunting grounds claimed by the Sioux, Cheyenne, and Arapaho, who were determined to keep the white man out of this region. Except for Indian resistance, Bozeman's route was by far the easiest route to travel.
Jim Bridger, in 1864, aware of the Indians' determination to keep the emigrants out of the Powder River country, pioneered a route leaving the Oregon/California/Mormon Trail west of Platte Bridge Station. Traveling north through the Big Horn Basin and west of the Big Horn Mountains, Bridger's route passed through friendly Shoshoni and Crow lands The Bridger Trail, though little used, proved to be a safe alternative to the more dangerous "Bloody" Bozeman Trail.
The determined resistance by the Sioux, Cheyenne, and Arapaho claimed many lives from 1863 to 1868, climaxing with the Fetterman Disaster in December of 1866. The federal government consented to the Indians' demands with the Fort Laramie Treaty of 1868 by closing the Powder River country trails and forts.