The Sonoran Desert is one of the most wildly diverse regions in the world. Covering southeastern California, the southern half of Arizona, most of Baja California, and much of the state of Sonora, Mexico, this vast area is home to an amazing variety of plants and animals. Its terrain varies dramatically, from parched desert lowlands to semiarid tropical forests and frigid subalpine meadows. This text provides a complete collection of Sonoran Desert natural history information and is an introduction to this biologically rich desert in North America.