有声读物: Pony Rider Boys in the Alkali

Yee-Haww! The Pony Rider Boys are on the move again! This time the boys are in the desert of Nevada, discovering the beauty and perils in 100 degree heat. It should be another thrilling ride that Professor Zepplin has taken them on! (Summary by Ann Boulais )

Previous book in the series: The Pony Rider Boys in the Ozarks
Next book in the series: The Pony Rider Boys in New Mexico