Robert W. Bob Audretsch first hiked to Phantom Ranch in 1977 and has logged nearly 10,000 miles on canyon trails below the rim. Audretsch worked as a park ranger at the canyon for nearly 20 years, retiring in 2009. During that time, he extensively studied its geology, natural history, and human history. This book shares his intimate knowledge of the Grand Canyon, along with his thorough research in archival collections.