Canyon Ambush

As United States agent Johnny Mack Brown rides into the Wyoming Territory, he witnesses a masked man on a black horse kill a wagon driver. Johnny stops the runaway carriage and brings its dead driver to nearby Border City. There, journalist Marian Gaylord chastises Sheriff Bob Conway for failing to halt the area's recent crime wave. Upon hearing that the townsmen have called a meeting that day to fire him, Bob, who has been foiled in all of his attempts to fight the criminals, quits in disgust. Just then, however, Johnny enters his office and, after revealing that he has been sent to help Bob, convinces him to don his star again. They attend the meeting together, identifying Johnny as the new deputy. Although lawyer Henry Lockwood leads the insurrection, Bob points out to the others that he has gotten all the suspects off on technicalities, and the men agree to let Bob try again. Later, Wells Fargo agent George Millarde confides to Johnny that a large shipment of money is arriving that afternoon, and when Johnny rides out to greet it, he sees three masked men ambush the wagon and kill the driver. Johnny once again stops the runaway wagon and brings the money to Millarde, who reveals that the only other person who knew about the shipment was his friend Bracket, a rancher. Johnny then receives a coded telegram stating that another government agent will meet him the next afternoon. When he goes to meet the agent, however, Johnny finds him murdered, and realizes that someone with a code book must be tapping the telegraph. He returns to the same spot with Bob the following day, and there they see three masked men attack a wagon driven by Marian. Johnny chases the bandits into the hills, and although he runs out of ammunition, he manages to escape. Johnny then instructs Marian to print a story that he is riding to the capital for an important meeting, knowing that when the bandits read it, they will attack him in the pass. He waits for them and ropes one, Fred Hodge. Hodge reveals that he gets his orders from rancher Carlton, who in turn reports to Lockwood. In order to uncover the identity of the gang's leader, Johnny sends a telegram to the authorities instructing them to arrest Lockwood. When Millarde visits and tips Johnny off that Carlton and Lockwood have left town, Johnny chases them, killing Lockwood and shooting Carlton in the arm. Carlton confesses that Lockwood works with Bracket, and brings Johnny to the shack where he received his instruction notes from Lockwood. In the shack, Johnny discovers a scrap of ledger paper. Marian has followed the men there, and when someone shoots at them through the window, Carlton is killed. Johnny sends Marian to round up a posse and chases the masked shooter through the hills. When the Bob and his posse arrive, Johnny and Bob race back to town to check Millarde's office. There, Johnny matches his scrap of ledger paper to the pad in Millarde's desk, after which he uncovers the contraband telegraph machine in the safe. Johnny waits until Millarde returns to his office, then tells him that Carlton is alive and ready to confess. Millarde accompanies him to jail, where Bob is disguised as Carlton. Millarde pulls a gun on Johnny and shoots both men, not realizing that Johnny has replaced the bullets with blanks. Johnny arrests Millarde, who tries but fails to escape. Later, Johnny announces to Marian and Bob that pioneers are now safely crossing the border to make Wyoming a state. The couple shyly reveal that they are engaged, prompting Johnny to question the legality of merging the law with the press.