PRESCOTT, ARIZ. — A participant in the Cocodona 250 ultramarathon died after experiencing a medical emergency during the race in northern Arizona, organizers confirmed. The race, which began Monday before dawn, will continue in the runner's honor.

A woman in her 40s collapsed at a trailhead in the Groom Creek community south of Prescott, in Yavapai County, where first responders attended to her. Race codirector Erika Snyder confirmed the participant's death and declined to provide further details at the request of the runner's relatives.

Snyder said aid stations along the course allow participants to eat, hydrate, and adjust equipment, and that a team of medical professionals is stationed across the course.

In a statement posted to Instagram, Aravaipa Running said, "Out of respect for the runner's family and loved ones, we are not sharing additional personal details at this time." The organization added, "Please keep the runner's family, friends, fellow runners, volunteers, and first responders in your thoughts. We are deeply grateful to this beautiful community."

The Cocodona 250 covers 250 miles (402 kilometers) on trails across northern Arizona, starting in Black Canyon City and finishing in Flagstaff. The course involves an estimated 38,791 feet of elevation gain, rising more than a mile (1.6 kilometers) in elevation twice, and reaches its highest point at 9,241 feet outside Flagstaff. The race tracker listed nearly 400 participants. The event has been held annually since 2021.

The race can last up to five days, and racers often nap on the ground along the course. In 2021, 21 competitors died during a 62-mile ultramarathon in China in freezing mountain conditions. In 2025, a runner died after collapsing during a 102-mile endurance race through the Colorado mountains.