Clarke then moved his family to the Rocky Mountains and undertook ranching with his second wife, a mixed-race Blackfoot woman named Good Singing. They established the Clarke Horse and Cattle Ranch in 1864. The inciting incident of the Marias Massacre was the murder of Malcolm Clarke on August 17, 1869. He was killed by Owl Child—a young Piegan warrior—and his comrades at the Clarke Ranch. Two years prior in 1867, Owl Child had stolen horses from Clarke as payback for the loss of his own horses, which he blamed on the trader. Consequently, Clarke and his son, Horace, beat and humiliated Owl Child in front of a group of Blackfeet. There were accounts from Blackfeet claiming Clarke had also raped Owl Child's wife, who was a cousin of "Coth-co-co-na". Other Blackfeet oral histories state that Owl Child's wife became pregnant from the assault, and gave birth to a child who was either stillborn or killed by tribal elders. The Piegan warriors first shot and severely wounded Horace, who survived. They then proceeded to the house where they shot Clarke in the chest before Owl Child ultimately killed him with an ax. Clarke's other children and his wife took shelter in the house and were unharmed. Clarke's murder created a climate of unrest in the region, as outraged white settlers demanded that the government protect them and suppress the outlaw Blackfeet. In response, the U.S. Army demanded that the Blackfoot Confederacy execute Owl Child, and deliver his body to them in two weeks. Owl Child fled North and joined Mountain Chief's Piegan band, which, although known for their hostility toward white settlers, did not conduct raids on the settlements. When the two-week deadline had passed, General Philip Sheridan sent a squadron of cavalry from the Second Cavalry Regiment, led by Major Eugene Baker, to track down and punish the offending party. Sheridan ordered:  If the lives and property of the citizens of Montana can best be protected by striking Mountain Chief's band, I want them struck. Tell Baker to strike them hard. Sheridan intended that the squadron conduct a dawn attack on the Piegan village; it had snowed heavily and most of the Blackfeet would be sleeping or staying inside to keep warm. This was a strategy he had used before, as he had directed George Custer to attack Black Kettle's band of Cheyenne in the Battle of Washita River. Following their father's death, Nathan and Horace Clarke intercepted the Second cavalry as they passed through the Prickly Pear Valley and received permission from Colonel Philippe Regis de Trobraind to join the expedition.