The Chang Tang, the vast, remote Tibetan steppe, is one of the most forbidding places on earth. Yet this harsh land is home to a unique assemblage of large mammals, including Tibetan antelope, gazelle, argali sheep, wild ass, wild yak, wolves, snow leopards, and others. Since 1985, George B. Schaller and his Chinese and Tibetan co-workers have surveyed the flora and fauna of the Chang Tang. Their research provides the first detailed look at the natural history of one of the world's least known ecosystems.