Pecos River

Outside the small Arizona town of Pecos River, a group of masked bandits hold up eyeglass peddler Smiley Burnette. Stagecoach driver Ol' Henry Mahoney comes to Smiley's aid, shooting one of the bandits in a wild chase before he and Smiley are rescued by The Durango Kid. The bandits, Whip Rockland and his sons, Sniffy and Mose, vow to avenge the death of their accomplice. In town, Steve Baldwin, Durango's alter ego, reports to Betty Coulter, the head of the Coulter Stage Lines, as her new employee. Unknown to all except Henry, Steve is an undercover government agent investigating a mail robbery and murder in Tucson. Steve has established a phony criminal background in hopes of getting in with the Rocklands, the suspected robbery culprits. Shortly after Steve gets settled at Coulter's, Henry's son Jack returns home from college in the East. Sniffy and Mose harass the newly arrived Jack, who defends himself by boxing as Steve watches with approval. When Steve takes Jack home, they find Henry shot to death. Later, at the cemetery Jack promises to bring his father's killer to justice. As Durango, Steve offers to help Jack and, over several weeks, teaches him how to shoot and ride. At the same time, Steve takes over Henry's job as the coach driver. After Smiley runs into the Rocklands, he tells Steve that the family reminds him of the holdup bandits. Meanwhile, Betty negotiates a contract to transport the monthly payroll of a large mining company. As she confirms the details with Steve, Whip eavesdrops outside, but is observed by Smiley. Smiley informs the sheriff, adding that he witnessed Steve speaking with Whip and riding away with him afterward. When Smiley informs Jack that he suspects Whip is Henry's killer, Jack follows Steve and discovers him at the Rocklands' cabin hideout. Jack overhears Steve agree to join Whip in holding up the stagecoach line and bursts in to intervene, but is quickly overpowered. Steve escapes and as Sniffy and Mose escort Jack out to a cliff, The Durango Kid rescues him. Jack brings a posse back to the Rockland hideout, but they find it abandoned. In town, Steve is posted as an accomplice in Henry's murder, and while he attempts to explain the truth to Betty, the sheriff arrives to arrest him. Despite Steve's revelation that the mining company has cooperated in a plan to set up the robbers by placing heavy stones in its otherwise empty payroll box, the sheriff remains suspicious. Steve insists that he must drive the coach as agreed upon with Whip. Meanwhile, waiting along the stagecoach's route, Whip suspects a possible plot against him and arranges with another gang to blow up a nearby bridge to add confusion during the holdup. In town, the sheriff hides inside the stagecoach as Jack, dressed as Steve, drives. When Betty offers to help, Steve locks her in a closet but later, Smiley lets her out. Shortly after the stagecoach begins its journey, Whip gives chase and is followed by Durango. The sheriff is wounded in the subsequent shootout, and both Whip and Durango leap aboard the coach. As Jack and Whip fight and tumble off the speeding coach, Sniffy and Mose come to their father's aid. Betty arrives with a posse and breaks up their fight. When the reins then snap on the stagecoach, Durango must save the sheriff and the horse team as they race toward the mined bridge. After the Rocklands and their accomplices are arrested and jailed, Jack and Betty remain in Pecos River while Steve and Smiley depart.