A man posing as Mark Henry is after Henry's oil land but Henry's niece is part owner and he needs to marry her off to his henchman Slager. Mountie Jim Sullivan arives posing as a wanted man and is soon caught up in the plot when Slager, wanting everything for himself, kills his boss and makes Jim a prisoner.
An old arrowmaker's daughter, while at the stream, meets a brave from another tribe. They become enamored of each other in the sudden positive way of the savage, and agree to meet at sunset. The chief of the tribe to which the girl belongs, covets and demands her of her father. The father consents, but the girl rebels. At sunset, she meets her lover and tells him what her fate is to be. He tells her that when the moon shines, he will come for her and take her away.
Steve Beaumont, an operative for the Cattleman's Protective Association, is assigned the difficult task of breaking up a murderous gang of rustlers led by Ed Brock and Strang. He takes Sheriff Webb, Judge Baxter, and rancher Ann Houston into his confidence, and works his way into the rustler stronghold and confidence by "turning rustler" himself.
Kirk Baxter has been sent to investigate murder and robbery involving gold shipments. Identifying a gang member by his bullets, he uses that man's horse to locate and join the gang. He learns the gang is tipped off to the shipments by a mine employee using carrier pigeons. But the next message reveals his true identity and he is made a prisoner.
Steve arrives looking for the person printing counterfeit bonds. He finds his man in Pop Ryland who has two sons and a stepson. The stepson doesn't want to be an outlaw like the other sons and helps Steve out by posing as the Durango Kid when needed and then leading him to the evidence he is looking for.
Ken Maynard's exceptionally intelligent horse, Tarzan the Wonder Horse, is the star of this western about evil cowboy Steve Frazer (Welch) who gathers horses for slaughter, whose meat is sold to pet food manufacturers. The wild horse Tarzan frees the doomed horses from their corrals, and Frazer convinces the Sheriff that Tarzan is a threat and can be shot on sight. Local cowboy Ken Benson (Maynard) and rancher Pat Riley (Kennedy) work together to clear Tarzan's good name and put Frazier behind bars for his evil deeds.
U.S. Marshal Rocky Lane arrives to help his friend Nugget whose shipments are being robbed. Learning the gang only goes for incoming shipments, he figures they are repacking the loot and having Nugget ship it out. So he hijacks the next outgoing shipment finding a box labeled tools contains gold bars. Then posing as an outlaw he makes a deal with the gang hoping to round them up. But the boss learns he is a Marshal and he is made a prisoner.
Marshal Johnnie Taggart, posing as an outlaw named "Ace" Braddock, comes to Bannack, Montana to restore law and order. But he is recognized by Kitty, co-owner with Clay Curtwright of the infamous Bull Whip saloon. But "bad-girl" Kitty keeps her mouth shut. When Johnnie's pal Andy reports a stage holdup, Curtwright's henchman, Ben Borden, talks the sheriff and Judge Holden into suspecting Johnnie. Johnnie reveals himself to Judge Holden as a government marshal, and the judge voices his opinion that Curtwright is the leader of the road agents, but voices it in the presence of his granddaughter, Louise Holden.
Leary is using the Express Agent's liking for alcohol to enable his men to steal insured packages. Then he claims the insurance. Railroad Agent Hartley is sent to investigate and suspecting Leary, he and the Sheriff plan to trap them the next time they try their scheme.
A bounty hunter wants to catch the Bandit Carson because he has a lot of people in his gang who are worth a lot of money. When he comes into White City he gets his first problems with Carson's son Lucas. After this incident Carson wants this man dead. They can catch him but not for a long time because he can escape with the help of Zoppo who the bounty hunter had helped a couple of days before.
A man named Tony is captured riding the horse of Lee Corey, a missing delivery man for a local mining company. Tony claims to have bought the horse from two men, but the sheriff believes he has murdered Corey and stolen the horse. Tony is sent to the gallows, but escapes hanging with the help of Corey's mistress and sets out to find the real killer.
Jack is orphaned as a young child when his wagon train is ambushed by Indians. Twenty years later, he rescues Rose from a runaway stagecoach. The two fall in love, much to the displeasure of Blaney. To put him out of the way, Blaney kills Jack's adoptive mother and frames Jack for the crime.
Jimmy Wakely wishes to sell to the government a group of wild mustangs which he has captured and trained for rancher Matt Blake. The competition is Flora Carter, the owner of a near-by ranch. The army colonel in charge decides to buy the winning horses of a cross-country race. Flora has her henchmen, led by Sam Phelps resort to foul means in order to try to win the race.
Tom Carter, his wife and his son Billy, live quietly on the family farm until a dispute arises between him and his rich neighbour John Price who organizes a punitive expedition against Carter. Billy is sent to Littleton by his father and when he returns he finds the house burnt down, his father killed and his mother injured. The cautious sheriff prefers to conclude to an accident despite Billy's insistance. So Billy decides to take the law into his own hands...
