The Lone Hand (1953)

"The untold story of the secret outlaw empire that ruled the Rockies!"

Zachary Hallock and his son Joshua are farmers who live in a frontier town that suffers the assaults of a band of outlaws. After the murder of a Pinkerton's detective, the farmers decide to unite against the bandits, but Hallock rejects the proposal. To the astonishment of his son and his fiancée, Hallock decides to join the outlaws.