The first Copper Canyon ultramarathon took place in Urique, Mexico, in 2003, and was organized by legendary ultrarunner Micah True, also know as Caballo Blanco. True—famously depicted in Christopher McDougall’s bestselling 2009 book, Born to Run—wanted the race to help preserve the local culture of the Tarahumara people, who dress in sandals, skirts, and long-sleeve tops and have an extraordinary capacity to run long distances. In 2012, the 58-year-old True went missing during a run in New Mexico’s Gila Wilderness and was found dead days later. Soon afterward, the annual race in Copper Canyon was renamed the Caballo Blanco Ultra in his honor. Myke Hermsmeyer, a 29-year-old Montana-based photographer who has been shooting ultras for several years, traveled to Urique in March to document the 15th anniversary of this infamous 50-mile race. The city of Urique, which lies at the base of the Copper Canyon, now organizes the race. “It’s like if you put a town at the bottom of the Grand Canyon,” Hermsmeyer says. The Caballo Blanco Ultra and festival is by far the city’s largest event of the year, but when the race was canceled in 2015 due to nearby drug violence, its future was in doubt. Only six nonlocal runners ran the following year. The Caballo Blanco Ultra returned in 2017, with more than 700 Tarahumara, about 80 Mexicans, and 60 other runners from around the world.