Great book explaining the deserts, especially the Sonoran Desert in Arizona. My grandson is interested in the causes of things, so he found it fascinating. He also is at the right age for the early reading books and this was perfect for him. There is even a glossary in the back of the book explaining the pertinent words used that are not in everyone's everyday vocabulary. Of course, there is plenty of repetition of sight words throughout the book as there are in every early reader, yet this is one of the more advanced early readers. It is a wonderful book for the primary level. This merits a Thumbs Up!