In late 1823, fur trapper Hugh Glass, guiding Captain Andrew Henry’s men through the Dakotas, is mauled by a grizzly bear while hunting with his half-Pawnee son, Hawk. After a fierce Arikara attack, Glass is left behind, with Fitzgerald and Bridger assigned to stay with him. Fitzgerald, fearing an Arikara attack, persuades Bridger to abandon Glass. Fitzgerald kills Hawk and deceives Bridger into leaving Glass half-buried alive.

Glass, after recovering some strength, starts his journey for revenge. He survives harsh conditions and encounters Pawnee refugee Hikuc, who helps him before being lynched by French Canadian hunters. Glass rescues Powaqa from the hunters, kills several of them, and escapes from the Arikara by using a horse’s carcass for shelter.

At Fort Kiowa, Bridger recognizes Glass’s engraved canteen. Henry organizes a search party, and Fitzgerald, fearing Glass’s return, flees. Glass is found and clears Bridger of wrongdoing. He and Henry pursue Fitzgerald, who kills Henry. Glass captures Fitzgerald and, recalling Hikuc’s advice, delivers him to the Arikara. The Arikara kill Fitzgerald, and Glass, spared by them, retreats into the mountains, visited by his wife’s spirit.