South of Rio

At his ranch outside Rio Blanco, Lon Bryson, the head of a crooked miners' and cattlemen's protection agency, plots with his men to kill Henry Waterman, the outspoken publisher of the local newspaper, and scare Rio Blanco's uncooperative banker at the same time. Bryson is concerned that Henry's editorials will encourage the local citizens to vote for statehood and thereby put an end to his lucrative protection racket. As the outlaws are about to rob the bank, Jefferson Lanning, a newly appointed Ranger, and his boss, Captain Dan Brennan, arrive in town, having been summoned by Henry's printer, Andrew Jackson Weems, and the town marshal, Travis. When the gang starts a gunfight outside the bank, Jeff fires on Bryson's men, but stops short upon recognizing his brother Bob among the outlaws. Taking advantage of Jeff's hesitation, Bob, who now goes by the name Mitchell, kills Henry, then rides off with the gang. Not wanting to implicate Bob, Jeff insists that he did not see Henry's attacker, but his story is not believed and he is forced to resign from the Rangers. Later, Andy greets Henry's daughter Carol, who has just arrived from Chicago to take over the newspaper, at the nearby train depot and accompanies her back to Rio Blanco. Guarding their stagecoach, which is also carrying a shipment of money, is Jeff, and when Bryson's gang chases the coach and shoots its driver, Jeff saves the driver and stops the coach from racing out of control. Although Jeff's heroics greatly impress Andy and Carol, who is unaware of Jeff's involvement in her father's murder, Travis remains skeptical. Soon after, in the saloon, Jeff overhears a man insulting the Rangers and punches him. A brawl ensues, and after Bob happens along and prevents the man from shooting Jeff in the back, a grateful Jeff asks his brother to give himself up, but Bob refuses. Later, Jeff finally reveals to Andy why he did not shoot Henry's killer and admits that he is determined to bring his brother to justice. An understanding Andy recommends Jeff to Jim Weston, the owner of the Rainbow Mining Company, who hires Jeff as his wagon boss. During his first assignment, Jim's wagons are chased by Bryson and his men, and Jeff allows his wagon to crash, then escapes on a horse. In addition to the ore on Jeff's abandoned wagon, Bryson discovers a mail bag containing $5,000. Unknown to Bryson, Jeff had planted the marked bills and loaded his wagon with poor grade ore, sending the valuable ore on a different route. Jeff then instructs Andy to publish a report in the paper stating that Jim has no way of identifying the cash. When Bryson later learns that the good ore arrived safely, however, he guesses that the bills are marked and, suspecting Bob of helping his brother, orders him to kill Jeff. Soon after, Jeff receives a note from Bob, who claims to have had a change of heart and asks to meet him the next morning. At the rendezvous spot, Bob attempts to ambush Jeff, but Jeff outmaneuvers his brother and flees unharmed. Later, Carol learns why Jeff was dismissed from the Rangers and confronts him. Unaware of Bob's relationship to Jeff, Carol accuses Jeff of being in cahoots with Bryson, then goes to Travis' office to swear out a warrant for his arrest. Before she can have him arrested, Jeff and Andy go to Bryson's ranch, where they overwhelm Bryson and search his house for the stolen money. After Jeff discovers a piece of the mail bag in Bryson's fireplace then finds the money strapped to Bryson's chest, Jeff and Andy escort Bryson to jail. Seeing Jeff's evidence, the marshal imprisons Bryson and deputizes Jeff, who then explains all to Carol. While Jeff leaves to capture his brother, Carol goes to retrieve Jim so that he can identify the stolen money. Soon after, the gang breaks Bryson out of jail, and they all rush to intercept Carol. Bryson tries to force Carol to lead them to Jim's mining camp, but Bob intervenes and helps her to escape, but is wounded in the process. Andy, meanwhile, finds Jeff at Bryson's ranch and informs him about the jailbreak, and together they head for town to form a posse. On the way, however, they come across Bob, who tells them before dying that the gang is going to Jim's mine. While Andy goes town, Jeff races to the mine, where Carol and Jim are already preparing for the gang's onslaught. As Bryson and his men descend on them, Carol tells Jeff about Bob's sacrifice. After a fierce gun battle between the gang and the posse, Jeff pursues Bryson to some rocks, where Bryson finally meets his end. Later, at the Herald office, Andy reads aloud a newspaper report about Jeff's reinstatement in the Rangers, to the delight of Carol and Jeff.