After a handful of non-formula westerns, Charles Starrett returned to the mixture as before in Thundering Frontier. Starrett plays Jim Fillmore, kind to old ladies, small animals and heroine Norma Belknap (Iris Meredith). In contrast, the villains are kind to no one, least of all struggling building contractor Square Deal Scottie (Alex Callam), whose projects are continually targeted for demolition and his payroll is forever being stolen at gunpoint. A good 25 percent of the film's running time is given over to Bob Nolan and the Sons of the Pioneers, whose C&W croonings are pleasant but a bit much. One of the film's few surprises is that Starrett's perennial screen sparring partner Dick Curtis isn't one of the bad guys.
Wanted by the law in New York, Dr. Steve Kells heads west and arrives in an area controlled by an outlaw gang known as the Border Legion. When the gang's boss is wounded, they kidnap Kells and force him to remove the bullet. Not allowed to leave and being a wanted man, he joins the gang. Now wanted as a gang member also, he nevertheless plans a raid that will lead the entire gang into a trap.
Atkins is the boss of one of the Pony Express relay stations. He has been causing trouble and is replaced with Cal Sheridan. Atkins now gets the Richard brothers to raid one of the relay stations and they kill Norma's father. Cal sees that the horse of one of the raiders has a broken shoe and Norma sets out to find that horse.
A fast-paced, enjoyable entry in the long-running Three Mesqueteers Western series, Heroes of the Saddle featured the three cowboy pals promising to look after Peggy Bell, the little daughter of mortally wounded rodeo champ Montana. Legal technicalities, however, halt the adoption proceeding and Stony, Rusty, and Rico can only watch as the little girl is placed in the county orphanage.
Bill Ralston arrives in town planning to settle down but quickly gets caught up in the fight between the townspeople and Poe Daggett and his gang. He takes the job of town Marshal and soon brings law and order. When Daggetts men ambush him he kills Poe's brother. Poe then kills Bill's friend Brant and this leads to the showdown.
The Range Busters head for Pinto Basin where a series of stage robberies have occurred. To try and find the gang's boss, Crash sends out a empty money box. The plan backfires when the boss has the Range Busters identified as the robbers. Thinking it is now safe, the bank sends out a big money shipment. Needing to rob the stage, the boss gets the boys out of jail so they can be blamed. But this is just the chance they need to catch the robbers.
A lawyer by training, Bob Millburne (Don "Red" Barry) believes in relying on the legal system to exact justice. But he can no longer sate his thirst for vengeance, fueled by the death of his parents at the hands of a bloodthirsty mine jumper. Frustrated and fed up, Bob decides it's time to dust off his guns and holsters.
Bill learns that two con artists whom he has dealt with before are at it again. Crowley runs the saloon and Adams the newspaper and both are highly respected by the citizens. Bill has foiled their schemes before and this time he breaks into Adams' office and resets the front page saying Adams confesses to be a fugitive criminal. When the citizens gather the next day the end is near for Adams and Crowley.
Marshal Tim Donovan has been sent to investigate a series of holdups. Posing as a card sharp he soon believes he knows who is tipping off the outlaws. So he sets up a fake shipment knowing that if the stage is robbed the contact person will be identiifed. But the day the stage is due the Sheriff arrests the gang Tim was expecting to do the robbery.
Storm is out to wreck Ace's stage line. When Tex arrives to help Ace, Storm brings in hired killer Mule Bates. But Tex and Bates know each other and the two devise a plan to fool Storm.
Texas Ranger Dusty Rivers ("Isn't that a contradiction in terms?", another character asks him) travels to Canada in the 1880s in search of Jacques Corbeau, who is wanted for murder. He wanders into the midst of the Riel Rebellion, in which Métis (people of French and Native heritage) and Natives want a separate nation. Dusty falls for nurse April Logan, who is also loved by Mountie Jim Brett. April's brother is involved with Courbeau's daughter Louvette, which leads to trouble during the battles between the rebels and the Mounties. Through it all Dusty is determined to bring Corbeau back to Texas (and April, too, if he can manage it.)
Bill Hickok, assisted by Calamity Jane, is after a foreign agent and his guerrilla band who are trying to take over some western territory just as the Civil War is coming to a close.
Frontiersman Tom Garfield and his pals endeavor to save their land from the clutches of slimy easterner Forsyth. The villain hires a bit of local muscle in the form of brutish Chris Matson, but he's no match for our hero.
Richard Dix stars as Dave Morrell, the new marshal of Goliath, Oklahoma. Immediately upon arrival, Morrell finds himself at odds with banker Coy Barrett (Victor Jory), who is actually the leader of all local criminal activities.
Jim Sanders (Don 'Red' Barry), young cowboy, returns to his hometown for a reunion with his boyhood friend Clay Blackburn (George Offerman Jr.). Once there he learns that Clay's father, Frank Blackburn (Ivan Miller), is the unscrupulous proprietor of a stagecoach line and is out to bankrupt the line run by Joel Hunter (Griff Barnett' ), the father of Jim's sweetheart Ruth Hunter (Betty Moran). Jim is forced to lead the fight against his best friend.
When Moreland's henchman attack Bob Horner the Range Busters break it up. Horner dies but they get the baby Moreland was after. He must have it to become it's guardian and take control of the Horner ranch. When the henchmen catch up with Alibi, they take the baby cradle not realizing Alibi has substituted his dummy Elmer. Crash having evidence Moreland is the one they want, now has a plan to expose him.