Boy the Wonder Horse

Yak arrives at the Gilmore ranch where rustling has occurred. Gilmore blames a wild horse when it is actually his foreman Mays. After Yak catches and tames the wild horse, Mays gets Yak out of the way by having him arrested for murder. Mays and his men can now make one last raid. (imdb)

Horses are being rustled by outlaws known as the Hell Hounds. When the Sheriff is killed, his Deputy Yak takes over the search for the rustlers. John Lawson says Yak cannot marry his daughter until the murderer of the Sheriff is caught. But unknown to Lawson, the murderer is his own son. (imdb)