RunFastAbout the race
The Life Time Leadville Trail 100 Run, nicknamed the Race Across the Sky, is a 100-mile ultramarathon high in the Colorado Rockies. It starts and finishes in the old mining town of Leadville and is one of the oldest and best-known endurance running events in the world.
History
Ken Chlouber, a local miner, created the race in 1983 to bring attention to Leadville after the Climax Mine closed. In that first year 45 hardy runners tackled the course, which starts at 10,200 feet and rises to 12,500 feet. The organiser marked the 40th anniversary in 2023. Finishers chase a silver or gold belt buckle.
The course
The course is an out-and-back, beginning and ending in Leadville. The organiser lists the steep climb of Powerline, high passes such as Sugarloaf and technical stretches on the Colorado Trail, adding up to more than 15,000 feet of climbing. The high point is Hope Pass at 12,500 feet, crossed twice on the way. For 2026 the organiser used a revised route near Turquoise Lake to avoid areas affected by the Willow Fire, heading west from Harrison Avenue and circling the lake in the opposite direction, then rejoining the traditional course at the Outward Bound aid station.
The 2027 race
The organiser lists the next edition for 21 August 2027.
Entry basics
Runners must be 18 or older on race day. The 2027 lottery is open from 1 to 15 December 2026, with results due on 6 January 2027, and the organiser's Lottery and Qualification page explains the other ways to get in, including charity entry. Deferrals have their own policy page, and 2027 pricing was still to be announced. The organiser also keeps an Official Rules page, which is the place to look for cut-off times.
Where to watch
The race is centred on the town. The free, open-to-the-public Race Across the Sky Expo is held in downtown Leadville for check-in and swag bag pick-up, with live podcasts, bike demonstrations and a beer tent for friends and family. Much of the course is on remote public land, so many supporters stay in town for the start and finish.
Weather
August is summer in the high Colorado mountains. At this altitude conditions can change quickly between sun, cold and storms, and the weather varies from year to year, so runners and supporters should check the local forecast before the race.