The Civil War has just ended and the veteran Captain Kirby York (John Wayne) is assigned to to rural Fort Apache replacing its the gregarious commander. Kirby expects to take charge but is disappointed when the command of the regiment is given to Lieutenant Colonel Owen Thursday (Henry Fonda). Thursday led in the war, but is arrogant and lacks experience dealing with Indians. When Indian unrest leads to conflict, Thursday ignore York's suggestion to treat the Indians with respect. Now York must attempt to somehow broker peace between the Commander Thursday and the Apache Nation.