Phantom Ranch is nestled in the Grand Canyon basin on the Colorado River--a location hardly visible from the rim and only accessible after a journey through scores of geologic layers. The only way there is by river rafting, hiking, or mule, and with each foot of the journey, the traveler descends 30,000 years in geologic time. While at Phantom Ranch, the view looking above is of 1.7 billion years of geology, all swirling together in an alphabet of...