U.S. Deputy Marshal Bronco who knows Jesse James from the Civil War is given the task of finding him. Bronco tries to convince Cole Younger, a member of the infamous James gang, to turn over Jesse James, who is a heartless killer.
Bronco's undercover efforts to turn four teenage wanna-be outlaws he caught is interrupted when a violent gang of outlaws decides to rob the same gold shipment. When the sheriff is killed, the town threatens to lynch Bronco for it.
Bronco is working undercover on a cattle drive as a Pinkerton man looking for a man. Bronco's lovesick friend is up on robbery and murder charges, of which he isn't guilty, and Bronco has to clear his name and unmask the real killer.
Bronco, an Army Scout, arrives at Ft. Monument escorting the commander's wife not long after an Indian massacre has taken place leaving five enlisted men. He soon begins to suspect that the "survivors" aren't quite what they seem to be.
Bronco as ramrod for John Tunstall gets involved in a range war and is helped by outlaw Billy the Kid. However, after everything is settled, Billy still remains a wanted outlaw and is being pursued by bounty hunter Sheriff Pat Garrett.
After a cholera outbreak, Bronco is finally able to convince an army officer to send the Osage Indians to a fertile reservation in Wyoming before his death from the disease. But a hostile new commander may torpedo his efforts.
In order to find the outlaws who framed him for murder, Bronco fakes his own death and takes the identity of a colonist. He joins a steamboat of other settlers one of whom nearly exposes him until she realizes he might be innocent.
Bronco's after a killer and intends to bring him back alive, but a band of renegade Apaches plans to kill his prisoner in order to foment an Indian uprising while several whites are hoping he fails to start a war with the Apaches.
Bronco comes to the aid of the small rancher Joe Russo up against a brutal cattle baron to collect a debt owed Bronco. He winds up accused of murder when the cattle baron uses the herder's mentally unbalanced wife to get at him.
Bronco riding shotgun on a stage when it is attacked by Apaches is wounded. He is forced into dangerous intrigue involving a Mexican bandit who rescues them, a treacherous blonde girl who is a passenger and a cache of hidden gold.
Marshal Sample and Bronco are escorting a prisoner to the county jail they rescued from a lynching, but their job may be hampered by a vengeful mother who has sworn to kill the prisoner. When Sample is killed, Bronco must take over.
Deputy US Marshal Bronco chases an escaped prisoner from Montana to New Mexico. After a friend is murdered, He discovers a complicated scheme to protect outlaws on the run, and winds up sentenced to the gallows himself.
Bronco takes a job herding cattle cars, working for an arrogant boss who has a beautiful and flirtatious younger wife. During a fight, the boss falls off the train, and Bronco is blamed, but the man's body can't be found.
Army scout Bronco is to find out who's been killing and scalping Apache men, woman, and children. The chief's brother was among the last victims, and Bronco must find the guilty parties before the peace treaty is broken and war breaks out.
To save two Seminole friends, man and wife, from a lynching by former Confederates, Bronco tells them the story of how they tried to help the South in the war by bringing Jefferson Davis' peace offering to their chief in Florida.