Designed for the roadside traveler, this series explains in detail the geologic history of each of the western states as seen through the window. These books are a great introduction to basic geomorphology and how the dramatic landscapes were formed. Each section is organized around a particular route, with black-and-white photographs complementing the amazingly detailed geologic maps. The highly readable text lets you know exactly how and when that butte on the horizon was formed and how it fits into the larger geologic picture.  (USW188, $20.00)