Michael Kuhns has compiled a comprehensive guide to virtually every native and introduced tree species from the eastern slope of the Rockies west to the Sierra Nevada, and from north-central Oregon, the Salmon River region of Idaho, and Yellowstone south to the Grand Canyon and northern New Mexico. Included in the guide are simple and easy-to-use identification and classification keys, which are accompanied by hundreds of illustrations that introduce basic information on tree anatomy, climate/hardiness zones, and the individual species.