Sand Creek massacre
Guerrier's mother and an infant sibling died in an 1849 cholera epidemic. In 1851 Guerrier was entered in a Catholic mission school near present-day St. Marys, Kansas, and later enrolled in St. Louis University. After his father's death in 1857, Guerrier withdrew from the university and eventually returned to live with his mother's people, who knew him as Red Tail Hawk. He narrowly escaped death in the Sand Creek massacre in 1864.