National Geographic : 1955 May
( National ueograpnlc society 595 Kodachrome by Justin LocKe Down Jacob's Ladder! Guide and Dudes Ride Mules Almost a Vertical Mile to the River Nerves get a test on Bright Angel Trail's switchbacks. Mules pivoting around sharp turns lean outward, giving riders a clear view of thousand-foot abysses. This party approaches Indian Garden.