Fall Creek Beast
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Fall Creek Beast : Swan Valley, Idaho
The Fall Creek Beast is a trail race held on Halloween morning, October 31, 2026, in Swan Valley, Idaho. The event takes place at Rainbow Valley Ranch on Fall Creek Road and includes off-road trails and ridge terrain near Fall Creek.
The event features two distances with stated elevation gain:
- 50K, 6,000 ft elevation gain
- Half marathon (13.1 miles), 2,700 ft elevation gain
The course location is about 35 minutes from Idaho Falls, 45 minutes from Rexburg, and about 1 hour from Jackson Hole. Entry prices listed for 2026 are USD 99 for the 50K and USD 59 for the half marathon. Entries sold out in 2025 and the 2026 event is described as having limited space.
Organizers describe their priority as helping people experience the community of trail running, including early starts, shared effort, aid station interactions, and postrace camaraderie. The race name comes from a local 1868 folklore tale about the Swan Valley Monster, a legendary creature from the valley’s past. Visit the organization's website for the most recent information.