This challenging mountain trail run connects the four peaks of the Aspen Snowmass area—Aspen Mountain, Aspen Highlands, Buttermilk, and Snowmass—across some of Colorado’s most demanding high-altitude terrain. The event attracts both elite athletes and recreational runners, with local ski bums regularly pushing visiting pros to their limits in the thin mountain air.

Three distance options cater to different abilities and goals. The flagship 50K Ultra starts at Aspen Mountain’s base and finishes at Snowmass Base Village, climbing over 12,000 feet of elevation while starting at 8,000 feet. The course combines technical singletrack with fire roads, demanding both physical strength and mental fortitude as runners tackle all four peaks. Six well-stocked aid stations provide support along the route, though the gaps between them require self-sufficiency planning.

The 25K begins at Buttermilk’s Tiehack base, using the Government Trail to reach Snowmass Base Village. For those seeking a shorter challenge, the 10K starts atop the Elk Camp Gondola and traverses Snowmass before joining other finishers at the celebration.

The event’s mountain resort setting creates excellent spectating opportunities at each start location and the Fanny Hill finish area. All participants converge at Snowmass Base Village for the post-race celebration, fostering strong community atmosphere despite the event’s competitive edge.

Prize money rewards the top three 50K finishers in each gender, while podium ceremonies recognize the top three across all distances. The combination of serious competition, stunning alpine scenery, and the shared challenge of high-altitude trail running creates a memorable experience that tests every aspect of endurance running fitness.