Where the Great Plains meet the Rocky Mountains, this land was once a rich hunting ground and long-used natural route for nomadic people and migrating animals, lying hundreds of miles beyond the 1860 frontier in treaty-confirmed Indian country. John Bozeman brought a wagon road through it, following buffalo, Indian, and trapper trails to create a shortcut to the mining fields of western Montana, and miners soon turned those faint wheel marks into the Bozeman Trail. Sioux and Cheyenne in the high plains and mountains resented this trespass and the contempt it implied for a solemn treaty, and they made war until the Indians won a brief respite, helped by a railroad developing far to the south that ended the trail's shortcut advantage. On July 13, 1866, Colonel Henry R. Carrington arrived with four companies of the 18th Infantry and, by October, built the basic units of Fort Phil Kearny, a complete stockaded Indian Wars military post. The fort stood within an 800' x 600' stockade with cavalry and quartermaster corrals beyond it, a watering gap at the southwest end into Little Piney Creek, and the Bozeman Trail roughly parallel to the northeast side. Usually garrisoned by four to six infantry companies and one or two cavalry companies, the post was so closely invested by Sioux and Cheyenne warriors under Red Cloud that troops were often unable to convoy traffic on the Bozeman Trail. Hostile incidents were a daily rule, several famous Indian Wars engagements were connected with the fort, and after the military abandoned it in August 1868, a band of Cheyenne burned it.