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.
American federal agent Clark Stuart is on assignment in Santa Fe to draw up a trade agreement with the newly installed Mexican governor. Meanwhile, Walter Jamison leads a wagon train from Missouri, hoping to take advantage of the new agreement. Among Jamison's passenger are famed frontiersman Jim Bowie and a very youthful Kit Carson. The destinies of all these personalities intersect when villainous ex-governor DuPrey schemes to undermine the treaty and take over the New Mexico territory for his own vile purposes. Somewhere along the way, Davy Crockett joins the "good guys" in their efforts to thwart the despicable DuPrey.
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.
The spoiled, hard-partying son of a senator runs away from home after being reprimanded by his father, finds himself down-on-his luck in a tiny western town, and is rehabilitated through the friendship and wisdom of a kind and patient rancher.
A rancher finds that his stock of horses is mysteriously being depleted, and discovers that a ranch near him has had a sudden upsurge in its horse population.
Just after Kramer goes to Wyoming to start his protection racket, cowboy actor Jeff Carson finishes a picture and goes camping. Attracted to Joyce Butler, he hires on at her ranch and quickly gets caught up in Butler's conflict with Kramer. When the Butlers refuse to buy his service, he has their cattle stampeded.
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.
Kalmus is after the freight contract held by Summers. When his gang kill Summers, Tex and Duke step in to help Madge keep the freight line going. When they foil the gang's further attempts, Kalmus gets the Judge to jail the two.
Lawyer Bowdre has started a war between the ranchers and the homesteaders planning to take over the homesteaders land when they are wiped out. Rancher Dan Stockton, having just married homesteader Gail Dawson, is caught in the middle. He suspects Bowdre is behind the war and it's not long before he gets a chance to prove it.
A singing lawyer and other homesteaders participate in the Oklahoma land rush and found the town of Big Rock, but the fast-growing frontier settlement quickly becomes embroiled in political and business corruption. Director Noel Smith's 1937 western stars Dick Foran, Jane Bryan, Tommy Bupp, Ed Cobb, Frank Faylen, Tom Brower and Milton Kibbee.
When Johnny and Mendez argue, the lights go out, and in the ensuing gunfight Johnny thinks he killed his friend Dick. Now refusing to wear a gun he crosses the border. But it is not long before he runs into Mendez and more trouble.
Gene and Frog, out to stop a bunch of cattle rustlers, assume the identities of what they believe to be dead bandits, which soon gets them in big trouble.
Working undercover, Rangers Bob and Wally arrive to take up ranching. Out to stop them is Bill Nash and his men. When Bob plans to file on a ranch, Nash finds out and heads for the Registrar ahead of him.
Night riders are terrorizing homesteaders, and the town doctor tries to keep the locals from forming a vigilante group. After more towns people are killed, however, the rest of the town makes the doctor the town sheriff and tells him to clean up the gang.
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.
Dan Ward, reformed and last member of an outlaw family, meets Molly Clark in a rocky draw near town. Ted Wells, a henchman for Dan's enemy Jim Swain, attempts to shoot Dan but is outdrawn and killed by the latter. Molly disappears and Dan learns that she and Wells had ridden there together. Sheriff Bob Larimer tells Dan that Molly is in love with Bert Gilmore and tried to have him ambushed. Dan takes a risky job with mine owner Pember of getting the $10,000 payroll through to the mine. Swain suspects that Dan is carrying the payroll, but his gang is unable to stop Dan. Betty Pember disregards Dan's warning that the hills are filled with Swain's men and she starts for town. She is kidnapped by Gilmore and Molly and Dan ride to her rescue.
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.
Bank employee assigned to tell Arizona rancher her property is no good gets suspicious when her foreman agrees. Turns out his banker boss and the foreman know there's silver on that property.