In
Fort Smith, Arkansas, in the late 19th century, aging one-eyed
U.S. Marshal Rooster Cogburn is stripped of his badge by Judge Parker due to his drunkenness and questionable use of firearms. When a shipment of highly explosive
nitroglycerin is stolen from a transporting troop of
United States Army cavalry by the ruthless bank robber Hawk and his gang of nine outlaws, Cogburn is given a chance to redeem himself. Alone, he enters the
Indian Territory and tracks the bandits, who include Cogburn's former scout
Breed, to the remote settlement of Fort Ruby, which is now a
Christian mission. He comes upon the village the day after it has been overrun by the gang, who killed the elderly Reverend George Goodnight and a number of the local Indians. The only surviving inhabitants that have not fled are the Reverend's
spinster daughter, Miss Eula Goodnight, and one of her
Native students, a teenage boy named Wolf, whose family died in the attack. Cogburn tries to leave the pair at a nearby
trading post, but they insist on coming with him to capture the bandits. Because the nitro has to be transported slowly so it does not explode, Hawk goes ahead with Breed and an injured man to prepare for the bank robbery. Cogburn, Eula, and Wolf overtake the rest of the gang and barricade the path through a gully with logs. When the bandits stop, Cogburn says he is the leader of a
posse and threatens to blow up the nitro unless the criminals let him arrest them. One outlaw sneaks away and attempts to shoot Cogburn in the back, but Eula, proving herself an excellent sharpshooter, kills the man from across the gully. Cogburn shoots another man and Eula and Wolf make a lot of noise by firing into the air, and the outlaws flee, leaving behind the wagon with the nitro, which also has a
Gatling gun on board. They meet up with Hawk and take him back to the site of the ambush, where Breed determines that Cogburn lied about leading a large posse. The gang sets out in pursuit of the nitro and catches up with Cogburn's party that night. They kidnap Wolf, who has fallen asleep on his watch, and offer to exchange him for the explosives. Wolf shoots the man holding him and makes it back to Cogburn and Eula, and the trio is able to escape with the wagon after Cogburn has Wolf scatter the outlaws' horses. Coming upon a river, Cogburn commandeers a raft from an old ferryboat man named Shanghai McCoy, stashes the nitro and Gatling gun on board, and heads downstream, hoping to drop off Eula and Wolf somewhere safe before his final confrontation with Hawk. Breed and Luke, one of Hawk's men, are tasked with trailing the raft while the other members of the gang wait at a strategic
narrows. Luke suggests he and Breed double-cross Hawk by taking the raft themselves, but just as Luke is about to shoot Cogburn, Breed kills Luke, saying that, as Cogburn had once saved his life, they are now even. Breed warns Cogburn about Hawk's plan and then rejoins the gang, but Hawk does not believe him when he says Luke was killed in a shootout with Cogburn and knocks Breed off a cliff to his death. Cogburn is able to hold the remaining members of Hawk's gang at bay with the Gatling gun, but just past the narrows are some
rapids. Cogburn, Eula, and Wolf make it through safely, though the Gatling gun is lost. When they hear the gang's horses up ahead, the trio dumps several boxes of nitro overboard to float ahead of the raft. Eula and Wolf delay Hawk by saying Cogburn is injured and pretending to surrender, and Cogburn shoots the floating boxes, blowing up the last four outlaws. Back in Fort Smith, Eula convinces Judge Parker to reinstate Cogburn, even though he had stipulated Hawks be brought back alive. She and Wolf find some families to resettle Fort Ruby and part ways with Cogburn. The new friends hope their paths cross again someday. ==Cast==