River Of No Return Endurance Runs

JUN
20
2026
Trail ultramarathons in Challis, Idaho offering 32K, 55K and 108K courses with mountain climbs, mixed trail surfaces and multiple aid stations. Crew access and a final mile into town are part of the race experience.
Sat 20 Jun 2026
108 kilometers 55 kilometers 32 kilometers

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River of No Return Endurance Runs : Challis, Idaho

The River of No Return Endurance Runs are a set of trail ultramarathon courses that start and finish in Challis City Park, with the 32K beginning at the ghost town of Bayhorse and returning to the park via shuttle transport. The courses travel mountain country along the Salmon River corridor and pass historical mining areas and alpine scenery.

Distances offered:

  • 108K : about 17,600 feet elevation gain, 9 aid stations, large single-loop course.
  • 55K : about 8,800 feet elevation gain, 5 aid stations, lollipop loop with major climbs.
  • 32K : about 4,500 feet elevation gain, 2 aid stations, point to Challis City Park.

Terrain and route notes: much of the racing is on two-track ATV trail, with sections of single track, dirt road, elk trails, and a few paved miles approaching the town finish. The 108K includes five significant climbs and crests that reach roughly 8,000 to 10,000 feet. The 55K includes several climbs over 8,000 feet and a descent toward Bayhorse before returning via a looped section.

Support and logistics: courses are crew-friendly with multiple aid stations accessible by support teams without four-wheel drive. Crews may meet runners at specified aid stations and may accompany runners down Main Street into the final stretch. Pacers are permitted for the 108K after the Bayhorse Lake point. Refund and race change policies follow published deadlines. Visit the organization's website for the most recent information.

108 km
108k
55 km
55k
32 km
32k

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