After her father is killed, Mattie Ross (Kim Darby), a 14 year old girl, hires the drunken U.S. Marshal Rooster J. Cogburn (John Wayne) to find the killer, Tom Chaney (Jeff Corey). To do so, the pair must head into Indian territory, and are joined by a young Texas Ranger, La Boeuf (Glen Campbell), who also hopes to capture Chaney and collect a reward.