Molly wants a horse of her own, but when her father's mare gives birth to a mule, Molly changes her mind and raises the newborn.

Working to save the mules in their Kentucky community from being butchered at the cannery, twelve-year-old Scrappie and his friend Red Mule see their cause vindicated when tractors get stuck in the river mud and only mules can pull them out.

"Determined to recover his family's mules, fifteen-year-old Owen is joined by his kid brother and Telluride's notorious marshal in pursuit of a rustler--all the way to Butch Cassidy's hideout"--