Race Name
Leadville Trail 100 Run
The Leadville Trail 100 Run, also known as “The Race Across the Sky,” is a legendary 100-mile ultramarathon held in the Rocky Mountains near Leadville, Colorado. First staged in 1983, this event challenges athletes with extreme altitude and historic mining roads as they traverse high alpine terrain. Over forty years, it has gained iconic status among ultrarunners worldwide for its combination of rugged beauty and punishing climbs. Finishing this race earns competitors a coveted silver or gold belt buckle, solidifying their place in ultrarunning lore.
When it is run
Mid-August (typically the third weekend)
The Leadville Trail 100 Run takes place each year on a Saturday in mid-August, beginning at 4:00 a.m.. Starting near dawn at 9,200 feet, runners climb into thin mountain air as temperatures can vary from cool alpine mornings to warm afternoons. Weather on race day is notoriously unpredictable, with the possibility of afternoon thunderstorms or sudden temperature drops after sunset. Runners must prepare for rapid weather changes and manage hydration carefully under variable conditions.
How to qualify or register
Lottery, qualifier races, training camp, charity, or volunteer slots
Entry into the Leadville Trail 100 Run is primarily through a lottery held each December. Prospective runners may also secure guaranteed entry by earning a “qualifier coin” at one of the official Leadville qualifier events, completing volunteer service for 15 hours or more, or registering for a Paid Training Camp + Entry package. Charity entries and priority slots for Life Time Club members provide additional pathways. All lottery applicants submit credit card information when entering, and successful entrants have their cards charged on notification day in early January.
Particular challenges
High altitude, steep climbs, thin air, and weather swings
Competitors face a relentless ascent to Hope Pass at 12,532 feet twice—once outbound and again on the return leg. The cumulative elevation gain of 15,744 feet taxes cardiovascular capacity in thin air, and rapid altitude changes can exacerbate fatigue and nausea. Frequent afternoon thunderstorms pose risks of hypothermia near exposed ridgelines, while intense sun exposure at high elevations increases dehydration risk. Sleep deprivation compounds the difficulty, as runners must navigate dark forest trails and rocky outcrops under headlamp beams late into the night.
Course format
50-mile out-and-back dogleg
The race follows a single 50-mile out-and-back dogleg, starting and finishing on Leadville’s historic Mineral Belt Trail. Runners head out along the Colorado Trail to Hope Pass before returning the same way. This format allows pacers to join at the turnaround point, but requires competitors to retrace all terrain, including the toughest climbs and technical descents. The dogleg design emphasizes mental toughness, as athletes confront the same landmarks twice under different conditions.
Elevation profile
15,744 ft gain, 15,744 ft loss; low 9,200 ft, high 12,532 ft
Runners climb a total of 15,744 feet and descend the same amount over the course’s length. The starting elevation is 9,200 feet, rising steadily to the summit of Hope Pass at 12,532 feet around mile 15. The descent into Twin Lakes brings elevation back to 10,200 feet before the return climb. This symmetric profile tests both uphill power and downhill technical skills in high-altitude terrain.
Terrain breakdown
85% unpaved trails, 8% dirt roads, 7% mixed singletrack and gravel
Most of the Leadville Trail 100 Run unfolds on unpaved forest trails and mountain service roads, accounting for roughly 85% of the course. About 8% of the route follows wider dirt roads used for mining access, while the remaining sections include technical singletrack with rocks, roots, and switchbacks. The varied surfaces demand durable trail shoes with ample traction and protection, as footing can shift from hard-packed gravel to loose scree in alpine passes.
Time limit & cutoffs
30-hour overall limit; 11 aid stations with staggered cutoffs
Participants must complete the 100-mile course within 30 hours to earn a buckle, with the final cutoff at midnight following the race start. There are eleven staffed aid stations spaced approximately every 8–12 miles, five of which serve as medical checkpoints enforcing intermediate cutoffs. Runners who miss station deadlines are pulled for safety, but have the option to continue unofficially. Pacers may join competitors at the Ohio Creek aid station (mile 50), offering pacing support and access to drop bags for the second half of the course.
Aid stations
The Leadville Trail 100 Run features eleven staffed aid stations placed approximately every 8 to 12 miles along the out-and-back course. Major stations at Twin Lakes (mile 15), May Queen (mile 25), and East Fork (mile 41) offer full-service support with hot food, ice, and medical checks, while smaller water-only tables fill the gaps to ensure no section exceeds 12 miles without hydration. At the turnaround in Twin Lakes (mile 50), runners can access drop bags containing spare shoes, seasonal layers, and personal nutrition. Volunteer crews staff each station around the clock, providing both encouragement and safety oversight. Medical personnel are present at five checkpoints, enforcing intermediate cutoffs for runner welfare and tracking progress toward the 30-hour overall limit.
Mandatory gear
Competitors must carry essential gear throughout the race to ensure safety in high-altitude, remote conditions. Required items include two headlamps with extra batteries for nighttime navigation, a waterproof windbreaker with a hood for sudden storms, and an emergency blanket for hypothermia prevention. Runners also need to carry a personal first-aid kit, enough water-carrying capacity for the longest segment, and a nutrition reserve to span aid-station gaps. A fully charged mobile phone programmed with race-emergency contacts and a whistle for signaling are mandated by the official rules. Gear inspections at the start and midrace checkpoints enforce compliance, with disqualification for missing items.
Crew & pacing
Crew support is restricted to designated parking areas adjacent to aid stations, preserving the wilderness character of the course. Crews may hand off drop bags at these points but must not accompany runners beyond the aid-station boundary. Pacers are permitted only after the halfway turnaround at Twin Lakes, joining competitors to the finish line. This pacing allowance enables strategic support for the final mountainous climbs and technical descents but requires pacers to register in advance and adhere to all course rules. Vehicle access for crew and pacers is governed by race-issued permits and Forest Service regulations to minimize environmental impact.
Navigation
The Leadville Trail 100 course is marked with reflective armband ribbons, directional arrows, and mile signage at regular intervals. While GPS devices and digital maps are recommended to complement on-trail markings, runners must not deviate from the established route or follow unapproved shortcuts. Course marshals monitor key junctions, particularly on the exposed slopes of Hope Pass, to ensure adherence to the marked path. Participants are advised to carry backup batteries or power banks for electronic navigation aids, as race-day thunderstorms can drain batteries rapidly. Familiarity with the out-and-back layout is critical, as runners confront the same landmarks twice under differing light and weather conditions.
Finish rates
Historically, the Leadville Trail 100 Run sees an average finish rate of around 65%, with variation driven by weather, altitude acclimatization, and field depth. Cooler race-day temperatures and favorable conditions have pushed completion rates above 70% in select years, while afternoon thunderstorms and heat spikes can drop finish rates below 60%. The rigorous altitude and cumulative climb to 12,532 feet at Hope Pass contribute to non-finishers often withdrawing due to hypoxia-related fatigue. Data show that runners who earn a buckle typically complete the first 50 miles in under 16 hours, pacing themselves to meet the final cutoff at 30 hours.
Special features
Finishers earn a handcrafted belt buckle, with silver buckles awarded for sub-25-hour finishes and gold for those completing the course in under 24 hours. The gold buckle is exceptionally prized, symbolizing elite performance at extreme altitude. Unique to the Leadville series, multi-year finishers receive milestone buckles—5, 10, and 15 finishes—enhancing the race’s collectible tradition. The combination of historic mining roads, high passes, and scenic vistas of the Sawatch Range distinguishes the event as both a physical challenge and a celebration of the region’s heritage.
Previous winners
Notable course records include Matt Carpenter’s men’s time of 14 hours 30 minutes 20 seconds set in 2019 and Courtney Dauwalter’s women’s mark of 16 hours 45 minutes 10 seconds in 2021. Other legendary champions are Jenn Shelton, who won in 2008 and 2009, and Scott Jurek, who claimed back-to-back victories in 2003 and 2004. Tim Helsel’s consistent top-five performances across multiple editions exemplify veteran prowess at altitude. The roster of winners reflects both American and international talent, underscoring the race’s global appeal.
Official contact info
For the latest entry details, qualifying requirements, and volunteer opportunities, visit the Leadville Race Series official website at leadvilleraceseries.com. Race inquiries may be emailed to info@leadvilleraceseries.com. The Athlete Guide, containing detailed course maps, gear checklists, and medical protocols, is available for download under the “Resources” section. Social media updates and real-time alerts are posted on the series’ Instagram and X channels to keep participants and supporters informed.