Cattlemen's Protective Association agent Tom Wade masquerades as outlaw Luke Bardes, hired to help Jed Travis persuade his niece Jennifer to sell him her ranch at a ridiculously low price, enabling him to turn a huge profit when the railroad has to buy the right-of-way through his property. Tom finds himself in big trouble when Bardes breaks out of jail and shows up at the ranch with a few of his rough-and-trouble companions.
Jim Waters arrives at Ed Parks' ranch to find Parks' cattle herd mysteriously increased. Hamp Harvey has been losing cattle and he suspects Parks. But the culprit is Harvey's foreman Brent who gets his orders from the town's leading citizen Sig Barstell. Barstell wants Harvey's ranch and after trying to frame Harvey by killing Parks, Waters takes over and goes after both the killer and the rustlers.
An evil deputy is using Indian half-breeds to rustle cattle. This causes trouble between the cattlemen and Indians. Hoppy, Windy and Lucky see that justice is served. Songs abound.
Stan and Ollie try to deliver the deed to a valuable gold mine to the daughter of a dead prospector. Unfortunately, the daughter's evil guardian is determined to have the gold mine for himself and his saloon-singer wife.
Not quite a western, not quite a historical drama, Under Strange Flags is a little bit of both, and a lot of former RKO Radio cowboy hero Tom Keene. The star is cast as Tom Kenyon, a roving adventurer in Mexico during the Revolution. Hoping to protect the silver mine owned by heroine Dolores De Vargas (Luana Walters), Tom receives unexpected assistance from none other than rebel leader Pancho Villa (Maurice Black).
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.
When he swaps horses with the Tombstone Kid — a wrongly accused man on the run from the law — singing cowboy Tex Randall gets arrested by the local sheriff in a case of mistaken identity.
The fourth of 12 singing Westerns starring the "Silvery-Voiced Baritone," Fred Scott, Melody of the Plains begins peacefully enough with Scott, as cowboy Steve Condon, warbling Don Swander and June Hershey's "Albuquerque." The story quickly takes a rather grim turn when one of Steve's colleagues is shot and killed after selling out to a gang of rustlers. Mistakenly believing he fired the deadly shot, a dejected Steve, along with sidekick Fuzzy, goes to work for Bud's father, a rancher nearly forced into bankruptcy by a crooked land developer.
There is a range war between the ranchers led by Tilden and the outlaw gang of Link Carson. Wanted outlaw Dude Ramsey arrives and joins up with Tilden. First he saves the ranchers from Carson's trap and then exposes Pearson as Carson's informant and killer of Steve Warner.
Ted Haley rides to his brother's ranch and finds him dying from a knife wound. The brother names Sol Rothert as his killer. Leaving the house, Ted doesn't notice a mysterious man watching him, but he sees a rider gallop up to the house and enter, and Ted rushes to investigate.
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.
The Louisiana Purchase is imminent and Gilmore is smuggling guns into St. Louis so his men can make him Governor of the new Louisiana Territory. But John Colfax fights to defeat Gilmore.