"Many natural history books are catalogues of the plants and animals that are found in a particular region. This book is different. It tells a coherent story of how the landscape and features of a desert region evolved over time. The book starts with the explanations of the geological and climatological processes that shaped the desert since the late Mesozoic, leading to its current form. It also looks at the western Colorado Desert to see how it is similar and different from other desert regions around the globe. The focus then changes to the biology of the organisms that inhabit the desert and how they have adapted to the conditions that exist there. Faced with aridity, heat, and saline soils, plants and animals have taken many different evolutionary paths to deal with these factors. The result is an amazing biological diversity that has evolved in response to these conditions. Different organisms interact to form ecological communities that are distributed on the desert landscape. When humans first entered the region, they adapted to the desert landscape, harvested what they needed to survive, and began influencing changes to the desert landscape. The desert landscape has been profoundly changed by humans. Climate change and management of desert lands are today's real challenges. This book evolved from a desert biology course developed by Mike Wells and Marie Simovich over a 16-year period and taught at the University of San Diego. It was designed to educate the public about one of the great desert areas of the world that is encapsulated within Anza-Borrego Desert State Park. The author's support and dedication to this desert is expressed by their donation of royalties from the sale of this book to the Anza-Borrego Foundation"--