The Marias Massacre is a little-known one-sided battle that took place in Montana on January 23, 1870. Though receiving little attention in history, the massacre, which killed some 200 Piegan Indians, mostly women and children, was described by one company commander as “the greatest slaughter of Indians ever made by U.S. troops.”

Prior to this event, relations between the Blackfoot Confederacy, comprised of the Blackfoot, Blood, and Piegan tribes, and the white settlers had been hostile for several years. Amidst low-level hostilities in 1869, a young warrior named Owl Child stole several of horses from Malcolm Clarke, a white trader. Afterwards, Clarke tracked down Owl Child and beat him in front of his camp for the offense. Humiliated, Owl Child, with a band of rogue Piegans, sought revenge and killed Clarke.

The killing inflamed the public, which caused General Philip Sheridan to send out a band of cavalry led by Major Eugene Baker to track down and punish the offending party.

On January 23, 1870, cavalry received a scouting report that the group of Piegans, led by Mountain Chief, was camped along the Marias River. At first light, 200 dismounted U.S. cavalrymen lay spread out in an ambush position along the snowy bluffs overlooking the Marias River. As they awaited the command to fire, the chief of the camp came out of his lodge, walking toward the bluffs waving a safe-conduct paper. It was not Mountain Chief, who had been forewarned and had already left the area. Rather, it was Piegan leader Heavy Runner, who had enjoyed friendly relations with the white men. When an Army scout by the name of Joe Kipp shouted that this was the wrong camp, he was threatened into silence. Another scout, Joe Cobell, then fired the first shot, killing Heavy Runner and the massacre ensued.

In those early morning hours, the Indian camp was unprotected as most of the men were out hunting. Bullets riddled the lodges, collapsing some into smoking fire pits and suffocating the half-awake victims. When the carnage was over 173 lay dead – mostly women, children and the elderly. 140 others were captured, later to be turned loose without horses, adequate food, and clothing. As they refugees made their way to Fort Benton, some ninety miles away, many of them froze to death.