The Pony Rider Boys in the Rockies is a classic Western adventure novel that tells the story of two young boys who join the Pony Express. The boys, Billy and Jack, are orphans who have been living on their own in the wilderness. When they are offered a chance to join the Pony Express, they jump at the opportunity. The boys quickly learn the ropes of the Pony Express and become some of the most skilled riders on the trail. They face many challenges along the way, including outlaws, Native Americans, and the harsh weather conditions. But they always manage to deliver the mail, no matter what the cost.