Fort Vengeance

When a poker game ends in a gunfight, card cheat Carey Ross (Keith Larsen) and his brother, Dick (James Craig), escape into Canada, one step ahead of the law. Wandering into Saskatchewan, they join the newly formed North West Mounted Police, their knowledge of the Sioux proving invaluable when Sitting Bull attempts to incite the chief of the Blackfoots into joining his war against the white settlers. So when Carey murders a trapper and the chief's son is to hang in his place, Dick must bring in his brother if he's to stop the Blackfoots from joining the Sioux in a full-scale Indian uprising.