A mountain man who wishes to live the life of a hermit becomes the unwilling object of a long vendetta by Indians when he proves to be the match of their warriors in one-to-one combat on the early frontier.

A Mexican-American War veteran, Jeremiah Johnson (Robert Redford), heads to the mountains to live in isolation. Woefully unequipped for the task at hand, Johnson is fortunate to come across a seasoned mountain man (Will Geer) willing to teach him the necessary survival tactics. As life continues in the mountains, Johnson finds himself a native bride (Delle Bolton) and an adopted son (Josh Albee). However, their peaceful existence is threatened when Johnson incurs the ire of the Crow Indians.