ExtremeAugust

Leadville Trail 100 Run

Leadville, Colorado
100 miles

Race Across the Sky - Leadville 100 is a high-altitude monster starting at 10,200ft. The out-and-back course features climbs to 12,600ft and tests your ability to perform in thin air.

Race Overview

Distance
100 miles
Cutoff Time
30 hours
Finish Rate
45-55%
Entrants
~700
Terrain
Trail
Month
August

Terrain

Rocky jeep roads, exposed alpine trails, and high mountain passes above treeline

Entry Method

Lottery + qualifier requirement

Elevation Profile

Start: 10,200ft
High: 12,620ft
Elevation Gain

15,600 feet

Elevation Loss

15,600 feet

High Point

12,620ft

Low Point

9,200ft

Elevation Range: 3,420 feet

Key Course Sections

Start to Mayqueen

Easy
Miles 0-13.5+600 / -1,280 feet

Moderate climbing on Turquoise Lake trail. Runners must resist going too hard despite feeling good.

Mayqueen to Winfield

Extreme
Miles 13.5-50+7,800 / -7,120 feet

The gauntlet. Huge climbs over Hope Pass (12,600ft) and Twin Lakes. Altitude sickness is real.

Winfield to Mayqueen (Return)

Extreme
Miles 50-86.5+7,120 / -7,800 feet

Same terrain in reverse. Hope Pass is just as hard the second time. This is where races are won.

Mayqueen to Finish

Moderate
Miles 86.5-100+1,280 / -600 feet

Final push around Turquoise Lake. Mostly runnable but you're exhausted at 10,000ft elevation.

Recommended Pacing Strategy

Leadville is all about respecting altitude. Your normal pace means nothing here. Heart rate and breathing should dictate effort, not pace. Power hike all climbs and run the descents and flats conservatively to save energy for the return trip over Hope Pass.

Key Pacing Tips

  • Arrive 3-5 days early for altitude acclimatization
  • Hike Hope Pass both times - everyone does, even winners
  • Expect pace to be 2-3 min/mile slower than sea level
  • Breathing should never be labored - if it is, slow down
  • The return journey over Hope Pass (mile 60) ends many races

Get Your Personalized Pacing Plan

Upload the Leadville Trail 100 Run GPX file and receive a segment-by-segment pacing strategy tailored to your goal time, optimized for every climb and descent.

Common Challenges

  • Altitude (entire race above 9,200ft, peaks at 12,620ft)
  • Nausea and headaches from altitude
  • Cold nights (temperatures can drop to 30°F)
  • Dust from jeep roads
  • Mental challenge of out-and-back course

Recommended Gear

  • Warm layers for high-altitude nights
  • Buff or mask for dust protection
  • Trekking poles (highly recommended)
  • Extra electrolytes for altitude
  • Headlamp with backup

Course Location

Leadville, Colorado

39.2506, -106.2923

Leadville, ColoradoView on Google Maps →

Quick Stats

Distance100 miles
Elevation Gain15,600 feet
Elevation Loss15,600 feet
High Point12,620ft
DifficultyExtreme

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