ication system explains exactly what features to look for to tell one species from another. In each Peterson Field Guide, an author with expertise in the subject and an experienced artist work closely with the editors to ensure that both text and illustrations are accurate. This edition includes 100 color photographs of tracks and signs, more than 1,000 line drawings, and nomenclature for all the mammals of North America. The text includes descriptions of habits, habitats, tracks, signs, and ranges, and is filled with wonderful natural history stories. Olaus J. Murie, one of America's leading mammalogists, has completed fieldwork throughout the United States and Canada, from Labrador to the Aleutian Islands, with special concentration in the Northwest. He wrote The Elk of North America and many articles on natural history. Mark Elbroch is the author of several tracking guides, including two award-winning books, Mammal Tracks and Sign: A Guide to North American Species and, with Eleanor Marks, Bird Tracks and Sign: A Guide to North American Species. He has contributed to numerous North American research projects, from monitoring bears to capturing cougars to inventorying carnivores in dry tropical forests.