This book purports to be the journal of a two-week raft trip down the Colorado River through the bottom of the Grand Canyon. In addition to a superb account of the river journey as a wilderness adventure, the book records a series of conversations between scientists and nonscientists that range over the physical, natural, and social sciences. This book inspires me because it shows a natural connection between outdoor adventure and science as a natural response to looking at the world and asking “Why?” This book is no longer in print, but the author has created a beautiful on-line, multimedia version that combines his text with photographs and sound files from Leonard Thurman’s Grand Canyon River Running web pages. The on-line book can be accessed at http://williamcalvin.com/bk3/