Book excerpt: This book is written for visitors to Shenandoah National Park who appreciate the natural beauty of the park and want to learn about the fascinating geologic features. Readily observable geologic features are discussed at twenty-six different localities, twenty-five of which are accessible form Skyline Drive. Such features include the roots of the massive mountain chain that existed here one billion years ago, volcanic rocks, beach sands and their fossils, and a large fault associated with uplift of the Appalachian Mountains. Robert Badger has been studying geology in and around Shenandoah National Park since the early 1980's, first as a graduate student and more recently as professor of geology at the State University of New York in Postsdam.