Seeking a shorter way to the goldfields of Montana Territory, former prospector John Bozeman traced a route through the Powder River Basin—prized buffalo grounds for the resident tribes. A few hundred emigrants used the route between 1863 and 1866; later, as tribal resistance grew, it became primarily a military road.
In March 1866, when whites and Indians together at Fort Laramie mourned the death of Mni Akuwin, daughter of Spotted Tail, chief of the Brulé Lakota, a colonel at the post hoped it was a sign of peace between the peoples. Peace hopes were shattered later that spring however, by the arrival of hundreds of troops to build forts on the Bozeman Trail, and two more years of bitter warfare followed. Finally in 1868, the tribes of the northern plains gathered at the fort and signed a treaty, ending the war—for a while.
On Aug. 2, 1867, a large force of Oglala Sioux attacked woodcutters near Fort Phil Kearny. Soldiers assigned to protect the woodcutters took cover behind a ring of wagon boxes. After the intense battle, both sides claimed victory, and estimates of the dead and wounded varied widely.
When the U.S. Army in 1866 sent troops to build a string of forts along the Bozeman Trail north from the North Platte River to the Montana gold fields, Lakota, Cheyenne and Arapaho tribes in that country reacted angrily. For two years, the tribes harassed and attacked the soldiers and travelers on the trail. After the Treaty of Fort Laramie in 1868, the Army withdrew, the Indians burnt the forts and for a few years, until hostilities started up again in the mid-1870s, the tribes the country largely to themselves.
The U.S. Army established Platte Bridge Station in 1862 to protect the Oregon/California/Mormon Trail crossing of the North Platte River and the new transcontinental telegraph. After Lt. Caspar Collins was killed there by Cheyenne and Lakota Indians in 1865, the post was renamed Fort Casper, misspelling his first name. The fort was abandoned two years later, but reconstructed in 1936—and renamed Fort Caspar—with funds from the Works Progress Administration. Fort grounds and a museum are open to the public.