Geologist L. Greer Price worked for the National Park Service for ten years, mainly in Grand Canyon National Park, and his experience in explaining the geology of the canyon to the parks visitors is evident on every page of his brief (64-page) introduction, enlivened with dozens of photographs. Basic geological principles, including plate tectonics, structural features and their significance, and the role of erosion, are introduced and emphasized throughout; a glossary and a full index enhance the book's usefulness. Proceeds from the sale of the book benefit the educational programs of Grand Canyon National Park.