Bighorn 100

100 miles through Wyoming's Bighorn Mountains. A classic mountain ultramarathon with 21,000 feet of climbing and stunning high-altitude terrain.

Distance 100 Miles
Elevation 21,000 ft
Cutoff 36 Hours
Typical Date Mid-June

Quick Facts

Location

Bighorn Mountains

Near Dayton, Wyoming

Elevation Range

4,600 - 9,400 ft

High altitude challenge

Qualifies For

Hardrock 100

Western States 100

Terrain

50%+ Runnable

Mixed trail and dirt road

About the Course

The Bighorn 100 is one of America's classic mountain ultramarathons, traversing the Bighorn National Forest in northern Wyoming. The course features a mix of single track trails, dirt roads, and stunning alpine scenery.

With over 50% of the climbing in the 0-5% grade band, the course is more runnable than many mountain 100s. However, the high altitude (reaching 9,400 feet) and typical June heat create significant challenges. The 5.7 miles of steep climbing (15%+) and technical descents require solid mountain running skills.

The race starts and finishes near Dayton, Wyoming, with multiple crew-accessible aid stations throughout the course. A 52-mile option is also available for those seeking a shorter but still challenging mountain experience.