Pioneers of the Frontier (1940)

Wild Bill Saunders discovers that his uncle Mort has been murdered by an unscrupulous ranch foreman, Matt Brawley. But before he can right Brawley's wrongs, Wild Bill is arrested for a murder he didn't commit. Sidekick Cannonball Sims and disgruntled girl rancher Joan Darcy plot to break Wild Bill out of jail but Brawley is wise to their plan.