Though the hit song "Mule Train" is most closely associated with Frankie Laine, it was Gene Autry who first sang the tune on film, in a picture titled ... what else? .... Mule Train. This time, Autry plays a federal marshal who comes to the aid of a grizzled old prospector who has been framed for murder. The villain, Sam Brady (Robert Livingston), wants to appropriate the prospector's land, and he isn't particular as to how he achieves that goal. Leading lady Sheila Ryan plays a female sheriff who is on Brady's side at first, but who later realigns herself with Autry. Ryan later became the wife of Pat Buttram, who also appears in Mule Train in his usual role as Gene Autry's comical sidekick.