In recent years environmental scientists have focused on the co-called Critical Zone, where landscapes are treated as integrated systems that encompass bedrock, soils, water and sky and are teeming with life. The concept is intriguing to young minds, exploring the natural world in an integrated way that has not been imparted often in children’s literature. This book discusses how rocks become soil, movers of the Critical Zone such as gophers and other burrowers, how plants provide food and habitats for insects, birds, and animals, how the water cycle functions, the process of photosynthesis, and how humans are part of this vast system. In sum, it explains how all of life can be found in a thin outer layer called the critical zone.