This is the first comprehensive, up-to-date treatment of mammals in the state of Oregon since 1936, when Vernon Bailey's The Mammals and Life Zones of Oregon was published. It provides a basic reference for mammalogists, wildlife biologists, students, and anyone interested in mammalian life in the northwestern United States. Indeed, researchers in states adjacent to Oregon will find much useful information regarding the mammals their regions share with Oregon. Descriptions of all 136 extant or recently extirpated mammal species in Oregon are in the book, with information on geographical variation, diet, reproduction, ontogeny, mortality, and behavior. The authors provide range maps and lists of collection localities based on their examination of 55,265 museum specimens and brief accounts of morphology, species diversity, distribution, and fossil records. Keys to orders, families, and species are provided for identification of unknown specimens. Also helpful is the introductory section with its discussion of skull morphology, evolutionary history, basic taxonomy, zoogeography, zoonotic diseases, and the history of mammalogy in Oregon. A bibliography of 2,925 references makes the volume especially useful for anyone wishing to do further research.