Fort Pease was established in June of 1875 a few miles below the mouth of the Bighorn by Bozeman businessmen who speculated that it would serve as the head of steamboat navigation on the Yellowstone. For much of the winter of 1875-76, because it had been built on favored tribal hunting grounds, it was under constant harassment by the Lakota. With six trappers killed and eight wounded during the winter, the situation became so dire that the trappers sent for help from the military at Fort Ellis near Bozeman. Four companies of the Second Cavalry led by Major James S. Brisbin arrived in early March 1876 to relieve the fort, but although the Lakota had not been seen for a month and the trappers had resumed trapping and hunting, Brisbin had orders to bring the trappers back to Fort Ellis. Two days later, the cavalry and the trappers headed west as ordered, leaving the fort intact and assuming the Indians would burn it when they found it abandoned. Colonel John Gibbon's Montana Column arrived on April 19, 1876, and found the deserted fort virtually untouched, with the American flag still flying and a dog greeting the troops. The next day, dispatches from General Terry ordered Gibbon to continue patrolling the north side of the Yellowstone to prevent any Indian movement across the river, and Gibbon occupied the fort for two weeks while sending out scouting parties up and down the Yellowstone and as far south as Bighorn Canyon before moving downriver to the Rosebud confluence. After the Little Bighorn defeat, the Montana Column and the decimated Seventh Cavalry regrouped there and waited nearly a month for resupply and reinforcement. By late July 1876, the military had determined that supplying Fort Pease late in the summer would be difficult because of low water levels, and after discussion of building a fort at the Rosebud confluence, it instead chose the cantonment site at the confluence of the Tongue River, where construction on Fort Keogh began in early 1877.