Deputies Gene Autry and Frog go up against modern cattle rustlers. These rustlers use technology such as, airplanes, radios and refrigerated trucks to steal the cows, butcher them in the field and ship them out before getting caught. This causes the town to bring in a modern NYC detective to catch the crooks, but will Autry and Frog be permanently out of a job?
Cowboy Larry O'Day and his sidekick Lucky Smith happen upon a distraught Barbara Hartwell, who is about to be arrested for the murder of her uncle. With Barbara behind bars, Larry is determined to find the real killer and soon finds himself in the middle of a mystery involving crazed German entomologists and a smuggling ring bringing Chinese "picture girls" across the Mexican border for sale to wealthy Chinese bachelors.
Shortly after Brand kills Gelbert, Tom Rayburn arrives on the scene and is accused of the murder. Escaping, he goes after Doc Mathews, the man that can prove his innocence. Brand is also after Mathews and intends to keep him from testifying. But Mathews is a ventriloquist and this will lead to Brand's downfall.
Harris and Rigby own a circus. Rigby is a counterfeiter and frames his partner. The Mesquiteers learn Rigby is the culprit and get a confession from one of his men only to lose the case when the man is murdered in jail. The Mesquiteers try again and send Lullaby to try and win some of the fake bills in a card game.
A crooked real estate manipulator sells worthless land on mortgage to flood refugees, then tries to profit by reselling the land to the state, committing murder in the process, as the Three Mesquiteers work to bring him and his gang to justice.
Ace Beldon is in prison, but with his stolen bonds not recovered, Capt. Saunders has an idea. He sends Graham to prison and has him and Beldon break out. With Ranger Raymond assisting, they make their escape and get to the hangout run by Stone. But the plan starts to go awry when Sam overhears Graham talking with the Captain and reports back to Stone.
Jeff arrives in town to see the Sheriff only to find him just killed. The culprit is Clay Wheeler. When Jeff becomes friendly with Letty, Clay sends his man Ortega to kill him. Jeff foils the attempt and gets him to confess that Clay was the killer. With only old-timers Lafe and Bill to help, Jeff heads after Clay and his gang.
Unable to legally capture and sell a herd of protected wild horses, corrupt rancher Rance Macgowan uses his trained killer horse, Volcano, to substitute for the real leader of the herd and cause havoc and death among the ranches. With the government about to drop the restrictions on rounding up the herd, the Three Mesquiteers find themselves in the middle of the controversy after their friend, Sheriff Miller is killed by Volcano.
A lawman poses as an outlaw, steals $10,000 from a cattle thief, then promises to return the money if he can join the gang--while finding a way to expose them.
As the sheriff of a small western town, Autry sings his way into a relationship with Eleanor, a singer from a Chicago nightclub who earlier witnessed a murder.
In his film debut Ritter is sent to investigate miners being killed and their mines confiscated. The culprit is Evans and after Tex joins the gang, he is sent to kill two more miners. When Estaban is killed, Tex is put on trial for all three murders.
At the Texas Centennial in Dallas Autry confuses two girls by being himself and his own stunt double. When cowboy star Tom Ford disappears, Wilson gets his double Gene Autry to impersonate him. But Ford owes gangster Rico $10,000 and Rico arrives to collect. He fails to get the money but learns that Autry is an impersonator and now blackmails Wilson and his movie studio. Original version runs 71 minutes, edited version runs 59 minutes.