Grand Canyon attracts the attention of the world for many reasons, but perhaps its greatest significance lies in the geologic record that is so beautifully preserved and exposed here. The rocks at Grand Canyon are not inherently unique; similar rocks are found throughout the world. What is unique about the geologic record at Grand Canyon is the great variety of rocks present, the clarity with which they're exposed, and the complex geologic story they tell. This book tells the story of its marvels from beginning to now in words and pictures.