Frequently misidentified as a remake of the 1946 Roy Rogers movie, "My Pal, Trigger," this film has Rex Allen and his horse, Koko, joining a rodeo belonging to a young "senorita" whose father has been killed in a stunt horse jump. Only the audience knows that the father's partner (Tris Coffin) conspired with another rodeo star (Roy Barcroft, in one of his most vicious conniving henchmen roles) to arrange the "accident." The Barcroft character is jealous of Rex's stardom and causes an accident incapacitating Koko. Rex and sidekick Buddy Ebsen (future star of TV's "Beverly Hillbillies" and "Barnaby Jones") are contractually obligated to go with the show, so it falls to the young senorita and her governess (Mary Ellen Kay) to nurse Koko back to health - a process which bonds the horse and girl. When Rex gives his horse to her, Koko becomes the property of the crooked partner. The climax involves a race in which the stake is Rex winning back his horse, and trying to prove the murder conspiracy.