Under California Stars (1948)

Returning to his California ranch for some rest and relaxation, cowboy movie star Roy Rogers (Roy Rogers) finds himself drawn into battle with a dastardly group of horse rustlers. Taking pity on Ted (Michael Chapin), a young man who was disabled in a riding accident, Roy offers him a job on the ranch. But Ted's stepfather, Lige (Wade Crosby), leads a gang of thieves posing as wild-horse wranglers, and their prime target is Roy's famous horse, Trigger, which they kidnap for ransom.