In this remake of "Ride, Ranger, Ride" (1936), Texas Rangers Stony Brooke, Tucson Smith and Lullaby Joslin (The Three Mesquiteers) are detailed by Ranger Captain Miller, of the Red River Ranger Patrol, to seek an elusive Indian chieftain named Wanechee who is constantly stirring up trouble. They return and learn that a boundary change has placed their district out of the Rangers' jurisdiction, and it is now to be patrolled by the United States Army. Because of their familiarity with the territory,terrain and Indian ways, Captain Miller turns over the Mesquiteers to Colonel Langley, commander of the new army post. They are reluctant at first but the Colonel's beautiful daughter, Susan Langley, persuades them to stay with the assignment. They meet with considerable antagonism from Lieutenant Manning, Langley's second-in-command.