In 1959, John and Frank Craighead, along with a dedicated team of students and professional colleagues, began their pioneering and controversial study of the grizzly bear in the Yellowstone ecosystem. The Grizzly Bears of Yellowstoneis the culmination of that research. It captures both the history and the science of how the Yellowstone study evolved into a lifelong battle to protect and perpetuate the grizzly bear.John J. Craighead and his longtime research colleagues, Jay S. Sumner and John A. Mitchell, have brought together years of data detailing the natural history, reproductive biology, social behavior, population dynamics, and habitat use patterns of the grizzly bear population in the Yellowstone ecosystem from 1959 through 1992, as well as the results of complementary studies conducted by John Craighead in wilderness areas of Montana and Alaska. Their interpretations of the data have far-reaching management implications, not only for the grizzly but for the holistic management of large regional ecosystems. This study is an example of long-term ecological research that is unparalleled in its combination of foresight, continuity of effort, innovation of field techniques, and monumental scholarship.