What is the Leadville 100? Inside Colorado’s Toughest Race
Photo by Karah Levely-Rinaldi on Flickr
Colorado is a major destination for trail running, and is home to plenty of famous races. One clearly stands out as the toughest – the Leadville 100 trail run. Officially called the Leadville Trail 100 Run, it is one of the most grueling ultramarathons in the world.
Held each August in Leadville, Colorado, it spans 100 miles of mountainous terrain and extreme elevation, testing runners both physically and mentally. Many years, fewer than 50% of participants finish the race.
Here are a few quick stats that will put that into perspective:
- Start elevation: 10,200 ft
- Highest point: 12,600 ft (Hope Pass)
- Total distance: 100 miles
- Time limit: 30 hours
The race’s incredible combination of altitude, distance, and technical trails attracts elite athletes and a handful of amateurs every year.
The “Race Across the Sky”
Nearly the entire course of the Leadville 100 stays above 10,000 feet, with runners ascending alpine passes and ridgelines that feel sky-high, giving it one of the coolest race nicknames ever: the Race Across the Sky.
With multiple climbs over 11,000 feet and the iconic double ascent of Hope Pass, that moniker isn’t an exaggeration – the race quite literally unfolds in the sky. That’s part of what makes the Leadville 100 such a huge challenge.
Globally, very few endurance events operate at this altitude for such a long duration. Even seasoned ultrarunners struggle with reduced oxygen, faster fatigue, and slower recovery. Call it equivalent to hiking even one of Colorado’s easiest 14ers ten times back to back — an incredible feat.
What is the elevation gain of the Leadville 100?
The Leadville Trail 100 Run features a total elevation gain of 15,744 feet across its 100-mile out-and-back course.
Runners begin at 10,200 feet in Leadville and climb as high as 12,532 feet at Hope Pass, which they must summit twice. The course includes other major climbs as well, such as Powerline and Sugarloaf Pass. The low point is about 9,200 feet.
When did the Leadville 100 first start?
The Leadville Trail 100 Run was first held in 1983, the brainchild of local miner Ken Chlouber. After the Climax Mine shut down, Leadville was struggling economically. Chlouber believed a 100-mile footrace through the mountains could bring visitors to the town and help it become a tourist destination.
That first year, 45 runners showed up. Trails weren’t as well maintained as they’ve become since, and race support was also much less developed. However, the Leadville 100 caught hold and quickly earned a reputation as one of the toughest ultramarathons in the world.
Leadville 100 Course Records
Ann Trason set the women’s course record over 30 years ago in 1994 with a time of 18:06:24. That record still stands today and is one of the most respected performances in the race’s history.
The men’s course record was set more recently in 2024 by David Roche, who finished in 15:26:34. His time broke a long-standing record and set a new benchmark for the event.
Bill Finkbeiner holds the record for the most consecutive finishes of the race, having completed the Leadville 100 30 years in a row, starting in 1984.
Leadville Trail 100 Course Breakdown
The race follows an out-and-back course, starting and finishing in the town of Leadville. Much of the route runs along the Colorado Trail, beginning at 10,200 feet and reaching a turnaround near Winfield.
Major climbs include:
- Hope Pass (12,532 ft)
- Powerline
- Sugarloaf Pass
The trail is technical and uneven, with loose rock and steep grades. Weather can also shift quickly, with cold mornings, sun exposure, and sudden storms.
How to Enter the Leadville 100
Getting into the Leadville Trail 100 Run isn’t as simple as signing up. With high demand and limited spots, runners must go through one of several entry options to secure a place on the starting line.
You can enter through:
- An open lottery
- Select qualifying races
- Charity slots
- Leadville Run Camp
- Life Time Fitness member benefits
Each option has different costs and timelines, so plan ahead.
Most runners enter through the lottery, which opens every December 1st at 10 a.m. MST and closes on December 15th at 11:59 p.m. MST. You register on the official Leadville Race Series website.
Race Week & Expo
Race week in Leadville is a full community experience building up to race day. The Race Across the Sky Expo takes over downtown with:
- Local vendors and gear booths
- Live podcasts and media coverage
- Athlete check-ins and swag pickup
It’s open to the public and creates a welcoming, festival-like atmosphere worth arriving a few days early for.
On-Course Support
Runners are backed by a strong support network on race day. Volunteers staff aid stations, offering food, hydration, and encouragement. Many athletes use pacers to help them stay on pace late in the race. Crew teams manage drop bags, gear changes, and give mental boosts throughout the course.
What is the Leadville Trail 100 MTB?
The Leadville Trail 100 MTB is the mountain bike version of the iconic race, held on a similar high-altitude course. Launched in 1994, the event has grown into one of the most prestigious mountain bike races in the world. Riders tackle 104 miles of rugged terrain with over 11,000 feet of climbing, all at elevations ranging from 9,200 to 12,600 feet.
The course follows much of the same out-and-back route as the run, including climbs over Powerline, Sugarloaf, and Columbine Mine. The race is known for its steep climbs, fast descents, and the thin mountain air that pushes riders to their limits.
Entry is competitive, with riders gaining access through a lottery, qualifier events, or charity entries. Past competitors include big names like Lance Armstrong, Levi Leipheimer, and Dave Wiens.
Finishing times range from under 6 hours for pros to 12 hours for cutoff finishers. A sub-9-hour ride earns the coveted big belt buckle, while all official finishers receive a small buckle.
FAQ About the Leadville Trail 100 Run
How hard is the Leadville 100?
The Leadville Trail 100 is one of the most difficult ultramarathons in the world. Runners face high altitude, technical terrain, and massive elevation gain. In most years, less than half of the starters finish the race.
How do you train for it?
Successful finishers combine:
- Long-distance trail running
- Altitude training (or simulated elevation)
- Strength and mobility work
- Back-to-back long runs for endurance
Training also includes mental prep for long hours and unpredictable weather.
How long do runners have to finish?
There is a 30-hour time limit to complete the race. Runners must also meet cutoff times at several aid stations to continue.
What’s the prize?
Finishers earn:
- A silver belt buckle for finishing under 30 hours
- A gold buckle for finishing under 25 hours
- A finisher’s medal and race swag
- The respect of the ultrarunning world
Can anyone enter?
Yes – there are no strict qualifying standards. Entry is available via lottery, charity slots, or coaching packages that include guaranteed registration.
What makes Hope Pass so iconic?
Hope Pass is the highest point on the course at 12,532 feet. Runners must climb it twice, once each direction, making it the defining challenge of the race.
