This small field guide supposedly covers the extreme western United States, but many of the animals illustrated also range into the the Northern Rockies and western Canada so this book is useful for most of western North America. There are two pages for each of the 70 mammals, birds and reptile/amphibians. Every animal has a small-scale range map, overall sketch, sketch of its droppings, large sketch of forward and rear footprints and a sketch of the pattern left by several footprints. I found the latter especially useful since many times the individual tracks are not too clear, especially in sand or dry snow, but the track pattern provides a positive identification. This lightweight, pocket-sized format makes it convenient to carry. Highly recommended for hikers, campers and nature buffs.