Ouray 100 Mile Endurance Run
Ouray, United States • 17 Jul 2026
Ouray 100 Mile Endurance Run
The event is a 100 mile trail ultramarathon in Ouray, Colorado, set in the San Juan Mountain range and based at Fellin Park. The course includes about 41,862 feet of elevation gain across fourteen climbs. The final ascent tops out at the Bridge of Heaven, followed by a descent back to Fellin Park and the Ouray Hot Springs.
Runners must complete eight hours of volunteer service before July 1 or pay a $100 opt out donation to the local trail group. Entrants who have not submitted the service form or paid the opt out cost by July 10 will forfeit their registration and will not be permitted to participate. The service form is available from the event website.
The race is not a UTMB qualifier. Top finishers in the 100 mile event receive cash awards; payouts are subject to urine and/or blood testing for banned substances. The testing list includes steroids, testosterone, EPO, and THC. THC levels above 150 ng/ml will trigger a positive result.
Organizers require racers to carry a SPOT tracker, which will be provided and will send location updates every five minutes. The event maintains an old-school, low-frills approach, including an Ironton Clause that asks runners who drop before leaving Ironton to return to Fellin Park to support or pace other participants. Podium awards are laser cut from traffic cones. Visit the organization's website for the most recent information.