Badlands of Montana (1957)

Steven Brewster (Rex Reason), a candidate for mayor is ran out of a Montana town when he is tricked into a gunfight and kills his opponent. He takes up with a a gang of badlands outlaws and takes part in robberies, and is wounded and captured , Friends rescue him and bring him back to Helena, where he is elected sheriff. When his old outlaw gang attacks the town, he cleans them up but persuades Susan Hammer (Beverly Garland), the daughter of Henry Hammer (Emile Meyer), leader of the gang, to come over to his side and marry him.