Dolores Moreno (Ann Rutherford) desperately awaits the arrival of the money she needs to pay the taxes on her ranch, but Gene Autry (Gene Autry), the Pony Express rider carrying the funds, gets waylaid by bandits along the way. Stranded in the desert, Gene comes across a wild mustang, lassos him, breaks him and rides him to Dolores' ranch. There, he teams up with her trusted ranch hand, Frog (Smiley Burnette), to figure out a way to save the property.