A jaded veteran of the Mexican War (1846-48), Jeremiah Johnson (Robert Redford) seeks solace and refuge in the West. He aims to take up the life of a mountain man, supporting himself in the Rocky Mountains as a trapper. His first winter in the mountain country is a difficult one; he has a brief run-in with Paints-His-Shirt-Red (Joaquin Martinez), a chief of the Crow tribe, who observes a starving Johnson futilely fishing by hand.
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.