PTL - Petite Trotte à Léon is a 300km ultra marathon in Chamonix, France. Distance: 300km. Elevation: 25,000m D+. Difficulty: legendary (Challenge Rating 91/100). DNF rate: 50%. Time limit: 152h. Surface: off-trail. Established 2009.
PTL - Petite Trotte à Léon
Chamonix, Haute-Savoie, France
"300km around Mont Blanc. 25,000m climbing. Off-trail. UTMB's ultimate challenge."
A 300km semi-self-supported team circumnavigation of Mont Blanc.
The Course
Semi-self-supported team event circumnavigating Mont Blanc on a 300km route with 25,000m of climbing. Much off-trail.
mountainous
loop
5
Runner Experience
Self-supported race — runners carry all supplies. Checkpoints for timing and safety only.
Intimate finish in a remote setting. The camaraderie of shared hardship creates deep bonds between finishers.
Race Day Weather
10°C
-5° – 25°
55%
35%
Alpine late summer. Warm valleys, freezing high altitude.
Stats & Records
2009
80
Entry
€250
December
—
Lore & Trivia
La Petite Trotte à Léon (PTL) is the most extreme event in the UTMB family — and the most misunderstood. At approximately 300km with 25,000m of gain, PTL is not a race but a team mountain traverse. Teams of 2-3 runners navigate unmarked routes through the most remote and technical sections of the Mont Blanc massif, using mountaineering skills, map-and-compass navigation, and mutual support to cross high passes that other UTMB events avoid. There are no checkpoints in the traditional sense — just mountain refuges where teams can eat and rest. The name translates roughly as "Léon's Little Jog" — Léon being UTMB founder Catherine and Michel Poletti's dog. The irony is deliberate. PTL is the antithesis of the main UTMB event: no crowds, no rankings, no prize money, just three friends in the mountains for five days.
- ▸ ~300km with 25,000m of gain — the most extreme UTMB event.
- ▸ Teams of 2-3, not individual runners.
- ▸ Self-navigated — no marked course, no GPS waypoints provided.
- ▸ Named after the Polettis' dog Léon — "Léon's Little Jog."
- ▸ No rankings, no prize money — the only goal is to finish as a team.
- ▸ Mountain refuges serve as the only aid — teams carry survival gear.
- ▸ Requires genuine mountaineering skills: route-finding, exposure management, rope work optional.
- ▸ Time limit of approximately 152 hours (over 6 days).
PTL is what happens when UTMB trusts you to find your own way. Most people aren't ready for that trust.
Notable Editions
The Storm That Stopped PTL
Severe Alpine storms forced multiple PTL teams to shelter in emergency bivouacs above 2,500m. Several teams were rescued. The incident highlighted both the extreme exposure of the PTL route and the mountaineering competence required to survive it.
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Frequently Asked Questions
How long is PTL - Petite Trotte à Léon? +
PTL - Petite Trotte à Léon is a 300km (300km) ultra marathon with 25,000m of elevation gain. The course is loop on off-trail terrain.
How hard is PTL - Petite Trotte à Léon? +
PTL - Petite Trotte à Léon is rated legendary with a Challenge Rating of 91/100 (Extreme). The DNF rate is 50%. Runners have 152 hours to finish.
How do I enter PTL - Petite Trotte à Léon? +
Mountain experience, 100-mile+ finish. An application or essay is required. Entry costs €250. with a maximum of 200 starters.
What is the weather like at PTL - Petite Trotte à Léon? +
Average temperature is 10°C (range -5°C to 25°C) with 55% humidity and a 35% chance of rain. Alpine late summer. Warm valleys, freezing high altitude.
Are crew and pacers allowed at PTL - Petite Trotte à Léon? +
No crew access is permitted. Pacers are not allowed. Mandatory gear is required. Self-navigation is required.
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