South of Rio

An undercover Texas Ranger runs into trouble when he learns that the murderer he's trailing has a twin brother.

The Texas Rangers send Dave and Chito into the badlands to see if they can locate a counterfeiting operation. They arrive posing as wanted outlaws and this gets them into the gang. But as soon as they uncover the operation and locate the printing press, one of Chito's girl friends arrives to expose their identity and they find themselves trapped by the entire gang.

Having fled to Mexico from the U.S. many years ago for killing his father's murderer, Martin Brady travels to Texas to broker an arms deal for his Mexican boss, strongman Governor Cipriano Castro. Brady breaks a leg and while recuperating in Texas the gun shipment is stolen. Complicating matters further the wife of local army major Colton has designs on him, and the local Texas Ranger captain makes him a generous offer to come back to the states and join his outfit. After killing a man in self-defense, Brady slips back over the border and confronts Castro who is not only unhappy that Brady has lost his gun shipment but is about to join forces with Colton to battle the local raiding Apache Indians.

Sayres and his outlaw gang operate out of a town just across the border and out of the jurisdiction of the Texas Rangers. Ranger Bob Allen is sent across the border where he poses as an outlaw hoping to lure the gang back into Texas. He gets into Sayres' gang displacing the gang boss but the disgruntled ex-boss is able to expose the hoax and Bob is made a prisoner.

With thousands of cattle being rustled from White Sage ranch the 1930's Texas Rangers are called in. They manage to get one of their agents into the gang by making them think he is the Pecos Kid on the lam.

When Tim Barrett rides into Carabinas, his reputation as a lawman precedes him. Rescuing Polly Loomis from the unwanted attentions of a saloon ruffian, he learns her mother married ranch foreman Nick Grindel shortly before her death, and left everything to him in her will. Nick has proposed marriage to his stepdaughter, and she fears violence if her hot-blooded brother Dick finds out. When a body is found at the Bow Knot, Tim barely rescues Dick from a necktie party and is deputized to investigate when Dick confesses to a crime he didn't commit.

Ten years after the Civil War has ended, the Governor of Texas asks Leander McNelly to form a company of Rangers to help uphold the law along the Mexican border. With a few veterans of the war, most of the recruits are young men who have little or no experience with guns or policing crime.

Texas Ranger Jake Cutter arrests gambler Paul Regret, but soon finds himself teamed with his prisoner in an undercover effort to defeat a band of renegade arms merchants and thieves known as Comancheros.

Cal Stanley goes undercover as a beef buyer in order to catch the gang responsible for stealing the area's cattle.

The Texas Rangers round up rustlers by masquerading as the same. Trouble ensues when while in disguise one of the Rangers is accused of a killing.

Someone has been stealing ore from a valuable smelting mine. One of the independent mine-owners victimized by the crooks is pretty Joan Manning, making the Rangers' mission a bit more pleasant.