In an old fort dedicated to the service of change of chivalry, show up three hired murderers and warn Lohman, the manager, who is about to get a stagecoach traveling in the former judge who unjustly condemned to five years in prison , and of course the husband murderer now promised the judge, Ruth, indicating further that brings a suitcase with many dollars. However, Lohman rejects the suggestion of the bandits. But when the judge and his girlfriend, the fort was attacked by Indians.
Forced to kill a young Abilene gunman in the line of duty, Sheriff Matthew Roberts, torn by anguish takes off his badge and leaves Kansas. Roberts becomes known as 'The Drifter', wandering restlessly through the west. In Arizona, he aids elderly rancher, Tom Duncan, Tom's granddaughter, Virginia and kid-brother Danny in their fight to save their small ranch from a crooked banker and his gang of outlaws.
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.
Legendary lawman Pat Garrett wins the Fourth of July buckboard race in a small Nevada town against the unscrupulous Fred Smith and pretty Lavinia White. Lavinia blames Garrett for sending her father Ivory White to jail for robbing 100,000 dollars. White, who has stashed the loot away someplace, is about to be released and plans to return the money to the express office for the sake of his children, Lavinia and Chad. Nasty Jim Judd forces Lavinia to help him rob the coach carrying Ivory and the money, counting on the fact that White will keep quiet for his daughter's sake.
Jode MacWilliams, a cowboy working on the Circle O ranch, has a crush on the boss's daughter, Peg. After his friend writes a love letter for him, an Indian steals and delivers it to Peg. Meanwhile, word of Jode's affection reaches Peg's father, who has a decidedly less romantic view of this young couple.
Benito a railway switchman, one day hears a bugle call and go across a squad of American riders. Fearing an invasion, will look for help, but no more than the making of a film. The appearance of Benito on the set coincides with an explosion of dynamite that does blow. That's how Benito enters into contact with the amazing world of cinema.
Hank Davis kills Jack Lewis to get his gold mine. Bruce Conway brings him in but then realizes Davis is the only one that knows where the mine is. Bruce and his pal Whitey rescue Davis from the lynch mob only to have Davis' gang catch them and leave them in the desert to die.
In the cattle town of Lost Valley, Buck Courtrey, saloon owner and political boss, covets Tharon, daughter of Jim Last, a small rancher; and when rebuffed, he has Last killed. Tharon swears revenge with her father's own guns and organizes a vigilante band to check Courtrey's activities. Learning that she loves Billy, a cowpuncher, Courtrey kidnaps and threatens to kill him unless Tharon agrees to marry Courtrey following his divorce from Ellen. Courtrey's wife informs Tharon of Billy's whereabouts, and she rescues him in time to join the townspeople attacking Courtrey's gang. Courtrey is pursued by Tharon, who kills him and returns to become Billy's wife.
Fellow convicts Cheyenne Harry and Buck Masters become even more bitter enemies when Buck agrees to tamper with the prison's books for the warden's greedy son.
For revenge the outlaw Morgan steals the Carruthers young son. Seventeen years later Carruthers arrives in the valley where Morgan, his gang, and the now grown Bob hide. After Morgan shoots Tracy, he tells Bob that Carruthers did it and sends Bob out after him. But unknown to Bob, Morgan has put blanks in his gun.