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.