Rangelands comprise between 40 and 50 percent of all U.S. land and serve the nation both as productive areas for wildlife, recreational use, and livestock grazing and as watersheds. The health and management of rangelands have been matters for scientific inquiry and public debate since the 1880s, when reports of widespread range degradation and livestock losses led to the first attempts to inventory and classify rangelands. Scientists are now questioning the utility of current methods of rangeland classification and inventory, as well as the data available to determine whether rangelands are being degraded. These experts, who are using the same methods and data, have come to different conclusions. This book examines the scientific basis of methods used by federal agencies to inventory, classify, and monitor rangelands; it assesses the success of these methods; and it recommends improvements. The book's findings and recommendations are of interest to the public; scientists; ranchers; and local, state, and federal policymakers.