Leadville Trail 100 Run

The Leadville Trail 100 Run takes place in Leadville, Colorado, on a high-altitude course that combines natural single-track with rugged mountain roads through the Rockies. The full distance covers 100 miles of demanding terrain, much of it above 10,000 feet.

Runners face thin air and significant climbing throughout, a combination that has made this one of the most storied ultramarathons in American trail running. The course winds through remote mountain country around Leadville, alternating between forested trail and exposed high-altitude stretches, with altitude itself becoming as much a competitor as the distance.