Describes the experiences of Smoky, the mouse-colored horse, from his birth on the range, his capture by humans, through his work in the rodeo and on the ranch, and his eventual old age.

Tim, an outlaw, and Scorpion, a horse with a fiery spirit, team up to dodge the authorities, soon developing such a strong bond that Scorpion develops the ability to warn Tim when he is about to make a bad decision--in love and in other concerns.

While spending their summer vacation with Uncle Frank and Uncle Bill, two city children discover and begin to explore what seems to be an old gold mine shaft, but find that it is guarded by mountain lions.