The efforts of crooked rancher Stephen Laban to force his local bank into an unsecured loan are foiled by Fred Hunter and Jake Robbins, and Laban vows vengeance on the pair; but he is temporarily thwarted by the arrival from the East of society girl Millicent Delacey. Knowing her weakness for social prestige, Hunter arranges to masquerade as the Duke of Black Butte, a visiting nobleman on a hunting expedition; Millicent and her social-climbing mother completely succumb to the duke's charm.
Bandit crew with mysterious masked leader is doing lots of crimes. Mauricio Rosales and his sidekick ride into town all incognito and stuff to set things right.
Two con-men from the East come out West to join up with Avery. They plan to steal the Lopez diamond from Don Lopez. With the drought, Lopez has sold all of his other jewels for gold so that he can take his people to a better place to live and work. Dean and Soapy try to protect Lopez, but Avery and his gang steal the gold and look forward to stealing the diamond necklace. When Maria offers to become partners with Barrit, it looks bad for Lopez.
In this Western, Ken Curtis, Columbia Pictures' low-budget answer to Gene Autry, romanced one of the studio's most beautiful starlets, Rita Hayworth-lookalike Dusty Anderson. She played Helen Wyatt, whose father (the rotund Guy Kibbee) loses his ranch to the hayseed singing group the Hoosier Hot Shots. Unbeknownst to Wyatt, the Hot Shots have been swindled by a couple of Eastern crooks (Ian Keith and Matt Willis) and consider themselves the lawful owners. Chased by the irascible Wyatt, the band members seek protection from aspiring singer Curt Stanton (Curtis), who they mistake for a gunslinger.
Rugged cowgirl, Nell Hagen sets out to retaliate for the hanging of her father Judd, who ruled their valley with an iron fist before the natives revolted. She is accompanied by her brothers, Ritt and Kirby, a hump-backed half-wit, and their sensuous cousin Julie Ann. The family then robs a bank, kills two tellers, enacts their revenge before heading for the border where their own family drama gets really mean and nasty.
Cheyenne Harry (Carey) and his pals, bent on helping their friend Rawhide Jack, attend a rodeo with the intent to win the prize for roping steers and to hand the winnings over to Jack.
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).
The Cisco Kid and his buddy Gordito arrive in town and learn that Cisco is supposedly dead. Not only that: Before his death, he is believed to have attempted to steal Susan Wetherby's land.
A stranger rides into Rainbow Valley where he's mistaken for a former resident who was believed killed in the Civil War and soon finds himself in opposition to local boss Tom Cherry, who seeks to find $100,000 stashed away by a Mexican general.
Jose Desmet, a butler, killed his employer because the latter, once a district judge, had long ago condemned Desmet's father, a well known gangster, to death. When Desmet tries to seduce Salazar's daughter, who is heir to a goldmine, kills a woman and the village doctor because they had found out that he was selling weapons to the Indians, a government investigator, Bill Walcome, together with the sheriff, sets out to put an end to Desmet's activities.
Two peanut vendors at a rodeo show get in trouble with their boss and hide out on a railroad train heading west. They get jobs as cowboys on a dude ranch, despite the fact that neither of them knows anything about cowboys, horses, or anything else.
Durango, a debt collector, arrives in the town of Tucson, where he is hired by a bank director called Ferguson, who refuses to pay him his fee afterwards. Durango is thrown in jail on a false accusation but manages to escape and teams up with a Mexican bandit to get even with Ferguson, who has concocted a complicated plan to rob a shipment of gold belonging to the people of Tucson.
Local "patriot's league" leader secretly kills off ranchers, buys up their estates, which are undermined with tin ore; Marshal and singing cowpoke team up to find villain and motive.
When the night watchman at the bank is gunned down during a robbery, he fingers Barton as the trigger man. When the trial comes up in neighboring Carson City, Gil finds a witness named Shepherd who says that Barton was with him on the night of the murder. Gil gets Barton off, but Shepherd soon cashes a check from Gil at the bank and that raises questions. His father, Judge Phalen, starts an action against Gil, and when his father is shot dead, Gil is blamed for his murder.
William Hart, a prospector in the west, who, with his wife and child sought vainly for gold day after day, while hope waned and starvation faced them. One day while alone save for Nellie, their little girl, Mrs. Hart is visited by two tramp Mojave Indians who, with threats of vengeance, make her give them food.
The scenes are laid in the Hudson Bay country in comparatively recent years and cover the life of a Hudson Bay factor, showing him as a young man assuming his business in the wilderness and, as was common in those days, taking an Indian wife that he had purchased of her father in Indian fashion.