One of North America's hardest 100-milers, carved through the Colorado San Juans
Other trail races within 51 miles
Starting and finishing at Fellin Park in downtown Ouray, this 102.1-mile loop through the San Juan Mountains is one of the most demanding 100-mile races in North America. The route climbs over historic mining roads and high alpine singletrack, including Camp Bird Road, Silver Basin, Imogene Pass Road, Richmond Trail, the Weehawken/Alpine Mine Overlook, Crystal Lake, Old Twin Peaks, and the Bridge of Heaven. With over 41,000 feet of cumulative gain, a high point of 13,365 feet, and roughly half the field finishing each year, this race is deliberately designed to test the limits of experienced ultrarunners.
Recommended for seasoned ultrarunners
Ouray, CO, United StatesJuly 17, 2026
Must meet custom qualifier requirements within the qualification window
Qualifying window: January 01, 2025 – July 17, 2026
50 miles in under 11 hours; OR 100K trail finish; OR 100M trail finish; OR 55 miles in a 12-hour timed event; OR 90 miles in a 24-hour timed event; OR finish at Quad Rock 50, Silver Rush 50, San Juan Solstice 50, Zane Grey 50, or a comparable mountain 50+; OR prior Ouray 50 or 100 finish within the last 3 years; OR a start at Ouray in the prior year. Contact RD for exceptions ([email protected]).
Complete 8 hours of volunteer service at a trail ultramarathon or performing physical trail work prior to July 1, 2026. Alternatively, make a $100 donation to Ouray Trail Group. Submit proof via the Service Form linked at ouray100.com.
Qualifying period: Through July 01, 2026
Submission deadline: July 01, 2026
| Location | Mile | Elevation |
|---|---|---|
Ironton Park Aid Station | 27.0 | 9,724 ft |
Richmond Trailhead Aid Station | 32.3 | 10,974 ft |
Crystal Lake Aid Station | 42.8 | 9,610 ft |
Fellin Park Aid Station | 59.0 | 7,726 ft |
Silvershield Trailhead Aid Station | 69.8 | 7,674 ft |
Weehawken Trailhead Aid Station | 80.0 | 8,783 ft |
Lower Camp Bird Aid Station | 110.3 | 9,777 ft |
Sign in to see cutoffs, crew access, drop bags, and services for every aid station.
Mid-July in the San Juan Mountains brings dramatic daily temperature swings. Temperatures at the Ouray start (~7,640 ft) typically range from 40-80°F during the race window, but above 12,000 feet temps can drop near freezing overnight with significant wind chill. Afternoon convective thunderstorms are common throughout July — lightning on exposed ridgelines and above treeline is a genuine hazard. Rain and hail can arrive with little warning. Runners should plan to be off exposed terrain before early afternoon, and race management explicitly allows cutoff leniency for runners who shelter during lightning. Despite warm starting conditions, all runners should carry emergency cold/wet weather gear for the full 52-hour window.
Course spends extensive time above 11,000 ft with a 13,365 ft high point; average elevation is 10,239 ft throughout
Afternoon thunderstorms are common in the San Juans in July; multiple exposed ridgeline sections require careful timing above treeline
Nighttime temperatures can drop near freezing above treeline; mandatory gear includes emergency Mylar blanket and lighter
Mountain weather can shift rapidly from clear to severe; runners will experience multiple full weather cycles over the 52-hour window
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