SWAN VALLEY, IDAHO
Fall Creek
Beast — 50K & Half Marathon Trail Race
Idaho's most terrifying trail race. Beware the Fall Creek Beast.
Swan Valley, Idaho · 35 min from Idaho Falls · 45 min from Rexburg · 1 hr from Jackson Hole
Register Now2025 sold out — 2026 is filling up fast. Space is limited.
Trail Is For
Everyone
Our entries cost roughly half what a typical race charges. That is on purpose.
Our biggest priority is helping people experience the community of trail running — the early starts, the shared suffering, the aid station laughs, the finish line hug from a stranger. We are not here to gatekeep trail and ultra running.
All are welcome. Just beware the Fall Creek Beast.
2025 sold out — 2026 is filling up fast. Space is limited.
Last Year's Beast
The Swan Valley
Monster
A legendary cryptid from a famous 1868 Idaho folklore tale — aquatic, fire-breathing, snake-like. Rainbow scales. An elephant-like trunk. A single horn. Poisonous green venom that killed every blade of grass it touched.
An old man crossing the Snake River in Swan Valley met it first, in 1868. He fired twice and watched it slip back under the water. When he returned with a wagon and help, the creature was gone — leaving fluorescent green blood on the rocks all the way back to the waterline.
This race is named for what came out of the water. Run accordingly.
Register Now