Like the highest mountain peaks, deserts are environments that can be inhospitable even to the most seasoned explorers. Craig Childs, who has spent years in the deserts of the American West-as an adventurer, a river guide, and a field instructor in natural history-has developed a keen appreciate for these forbidding landscapes: their beauty, their wonder, and especially their paradoxes. His extraordinary treks through arid lands in search of water are an astonishing revelation of the natural world at its most extreme.