Pals of the Pecos (1941)

Dan Burke is after a mail contract and Stevens through his henchman Keno is out to stop him. When Burke's son Larry brings the payroll he is murdered and the Three Mesquiteers blamed. Young Tim Burke breaks them out of jail and they start the timed mail run to obtain the contract. But Keno and his men plan to stop them by using dynamite to make a road block.