Trail runners on a hillside above Swan Valley, Idaho — the Fall Creek Beast trail race
OCTOBER 31, 2026·HALLOWEEN
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

Face the Beast
6,000 FT
50K Gain
2,700 FT
13.1 Gain
6AM · 9AM
Start Times
10.31.26
Race Day
Runner descending a rocky trail under blue skyTwo runners moving through sage toward snow-dusted mountains
(02) Philosophy

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.

See Pricing
Runners gathered around a campfire after the race, laughing together
(03) On Course

Last Year's Beast

2025 · 50K Winner
Gavin Weber
6:52:59 · 16 finishers
2025 · Half Marathon Winner
Easton Wakefield
2:12:00 · 35 finishers
Two runners moving up a hillside singletrackRunners on a dirt road below the power linesRunner refueling at an aid stationLone runner moving through golden Idaho hillsideAerial view of Fall Creek winding through the valleyRunner in a vivid orange shirt against the TetonsRunner with braids moving away through sage and grassRunner grinning with two thumbs up at the summitGroup of runners moving up the trail with headlamps before dawnFall Creek Beast trucker hats lined up on a tableLone runner climbing in the dark with a single headlampTwo runners moving toward a snow-dusted ridgeThree runners side by side crossing an open meadowTop three finishers on the red podium with mountain backdropPodium winners celebrating under blue skyRunner with bib 9 climbing a steep golden hillsideRunner in a headband descending a rocky pitch under blue skyRunner in a spider-web shirt on a forested trailLayered ridges and timbered draws above Fall CreekTwo finishers holding up bibs 6 and 9 in front of Swan ValleyString of runners climbing a steep golden hillside trailFinisher laughing with a volunteer under a bright sunburst
An American flag silhouetted against a deep dawn sky over Swan Valley
(04) 1868 · Legend

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.

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