Woman in Her 40s Dies After Collapsing in Arizona's Cocodona 250 Ultramarathon

A participant in the 250-mile Cocodona ultramarathon across northern Arizona died Tuesday after a medical emergency, race organizers and local law enforcement said.

First responders aided a woman in her 40s who collapsed at a trailhead in the Groom Creek community south of Prescott. Yavapai County Sheriff's Office spokesperson Paul Wick provided those details Wednesday.

Cocodona 250 codirector Erika Snyder confirmed the death but offered no further information at the runner's family's request.

Event organizers posted on social media: "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 race is going to continue in their honor. We ask all participants and crew to carry the memory of this runner with you on the trail."

Ultramarathons push human endurance limits, but deaths remain rare compared to participant numbers in a sport that has gained popularity worldwide, with events from Death Valley to the Himalayas. Last year, a Michigan woman collapsed and died in a 100-mile race in southwest Colorado mountains.

The Cocodona ranks among the toughest U.S. ultramarathons. Its course climbs more than a mile in elevation twice and runs through Sedona from Black Canyon City. Runners get 125 hours to finish along Arizona's iconic trails, according to CBS affiliate KPHO.

This year's race began Monday before dawn. Rachel Entrekin won overall Wednesday afternoon in Flagstaff, setting a course record before a cheering crowd.

Organizers plan a lottery registration system next year due to rising demand.

Aid stations offer food, water, and gear fixes, with medical professionals posted along the route, Snyder said. Runners often nap on the ground during the multiday event.