While in the Cimarron jail, wild and hot tempered cowpoke ""Screamer"" witnesses outlaw Ace Coffin commit the cold-blooded murder of a fellow bank robber. Knowing that there is a $10,000 price on Coffin's head, Screamer offers to help Crown track down the killer and his band of outlaws.

With a little help from his old gang, widely known outlaw Jud Starr slips the hangman's noose and begins a law breaking rampage over the entire Cimarron Strip. Upon discovering that Starr and his gang are using the Cherokee Outlet as a place of refuge, Marshal Crown sets out to track them down.

There is trouble in Cimarron when Jing McQueen, the drunken son of wealthy cattleman Mike McQueen, shoots a local preacher and burns down a livery stable. When the preacher recovers, he refuses to press charges, and McQueen is released from jail, leaving Marshal Crown to control an angry lynch mob.

When a potential range war heats up between cattlemen and incoming settlers in the Outlet, Washington sends U.S. Marshal Jim Crown to the Cimarron Territory to quell the dispute. Assigned to Cimarron City, Crown finds that there is no law in the town, and that he will receive no help from the Army.

Crown is forced to jail his old buddy ""Bear"", accompanied by sidekick Mobeetie, and his gang of renegade cowboys, when they go on a free-for-all drunk and terrorize Cimarron. Upon their release from jail, the cowboys discover that their boss, cattleman Hardy Miller, has lost his government land lease, due to the government favoring the movement of the incoming farmers and settlers. When Miller is forced to fire Bear and his group, they promise revenge against the settlers and vow to turn the Cimarron River bloody red.

When wanted killers/brothers Felix and Gene Gauge turn themselves in to Marshal Crown and proclaim self-defense in a killing, they become the prime targets of other bounty hunters. With a $15,000 bounty on their heads, a local wealthy rancher hires a couple of ruthless henchmen to gun down the two brothers.

When Wilcat Gallagher's Wild West Show hits Cimarron, trouble starts when the shows main attraction features the reenactment of a cavalry slaughter of Indians called, The Battle Of Bloody Stones. When Indians in the Cimarron territory become angry with the way that the battle is portrayed, conflict erupts between the Indians and Wildcat Gallagher's band.

Gang leader Arn Tinker gives 19-year-old gang member Whitey false information about their next robbery. Whitey winds up kidnapping Dulcey, promising her a safe return only after Tinker is arrested and hanged for his past crimes.

Cavalry veteran Sergeant Bill Disher is driven to drunken rage when his close friend Little Tom is killed in an accident. Disher bitterly blames the modernization and expansion of the West, and burns down Cimarron's funeral parlor.

When killer Dickie Vardeman is arrested for murder, Marshal Crown suspects the outlaw Vardeman clan will try to rescue him, and sends the killer by train to a neighboring town for trial.

With Marshal Crown out of town, acting Deputy Marshal MacGregor pursues escaped hired gunman Luther Happ. After tracking down the escaped fugitive and killing him in a shootout, the wounded MacGregor passes out and awakens in a Texas jail, where he is accused by Sheriff Jack Hawkes of murdering Deputy Luther Happ.

Marshal Crown tries to prevent the Houston clan from entering the Mocane Valley before it's open for settlement. The Houston's believe they'll have little competition for prime land because of the legend of a malevolent beast thought to lurk in the valley. When the wagon train is destroyed and most of its travelers killed, Marshal Crown and his men search for the culprits not knowing if their quarry is man or beast.

Mobeetie, a cowpoke with a cowbell around his neck, becomes a pain in the neck for Marshall Jim Crown during a heat wave, when a trainload of dynamite is stuck in the middle of Cimarron and the railroad can't move it for a couple of days.

When a band of wolf hunters, whose very success has put them out of business, are becoming a problem for the settlers of the Cimarron Strip. Broke and hungry, they resort to killing cattle for sustenance. Marshal Crown offers them a section of land to homestead, but their leader, Sam Gallatin, believes that the life of an outlaw is preferable to that of a dirt farmer.

Marshall Crown hires a one-handed gunslinger as a deputy, not realizing the man has assumed the identity of a slain lawman and is intent on avenging himself on members of his former gang who abandoned him after he was wounded in a payroll hold-up.

Marshal Crown "sentences" a trail boss to the position of Deputy Marshal in a nearby town to run concurrently with the hard-labor sentences his men are serving for various crimes. A vindictive judge releases the hardcases hoping they will cause trouble for their former boss.

Marshal Crown and his posse thwart a payroll robbery and capture or kill all the entire outlaw gang. The leader is sentenced to ten years in territorial prison, but Crown can't gather enough evidence to charge the youngest member. When the youth decides to stay in Cimarron, the marshal arranges for him to work with an reclusive horse trainer and the youngster takes to both the job and his new boss. His new loyalty is put to the test when the gang leader escapes from jail and returns to Cimarron seeking revenge.

Marshal Crown is shot while pursuing a murderous gang of outlaws who prey on isolated Indian villages. He is found, hidden and nursed back to health by Heller, a young woman who was raised by Indians but now works for the outlaw gang. Crown and Heller escape to Cimarron, but are pursued by the outlaws who want to punish Heller for her treachery.

Marshal Crown, during the course of an hauntingly foggy night, hunts for a killer who is butchering his victims. Francis tells crown about how police in London were unable to solve a similar set of killings earlier that year -- by someone who called himself Jack the Ripper.

Sergeant Clay Tice a free-wheeling cavalry veteran, clashes with his Sergeant-Major Chambers, a by-the-book disciplinarian. When the Sergeant-Major catches Tyce courting Dulcey at the Wayfarers Inn instead of searching for rustlers with his cavalry patrol, the junior non-com is given a choice of resigning or facing court-martial. Tyce resigns, then rounds up several malcontents from his old troop and stages a kangaroo-court in the Wayfarers Inn with Chambers as the defendant.

While escorting a man to his trial in New Mexico, Crown is attacked by a pair of outlaws and stripped of his badge and identification. While chasing the escapee, the pursuer becomes the pursued when a vengeful posse and a grizzled bounty hunter mistake Crown for a killer.

An ex-convict kidnaps Francis and forces Marshal Crown to assist him rescue a number of prisoners being shipped to federal prison on a special train.

Crown tries to help Major Covington capture his son, an expert with dynamite, who has deserted the army and joined a band of murderous marauders.

A would be homesteading family is so afraid after seeing two men lynched by a rancher's gang, they refuse to cooperate with Marshall Crown, until one of them blackmails the rancher.