One cool dawn about 20 years ago, architect Douglas Stroh sat horseback at the top of an 8-mi trail descending into the western Grand Canyon.
He’d left home in Prescott, Ariz., hours before, driving in darkness north to the trailhead near tiny Peach Springs. Though he hadn’t been on a horse since age 12, he mounted up and joined colleagues for the three-hour descent to Supai village, located 2,000 ft below the rim and home to about 500 Havasupai Indians.