Mont-Blanc Marathon 2026: 8 Races and a New Finish in Chamonix (June 25-28)
In short — From June 25 to 28, 2026, the Mont-Blanc Marathon brings 10,000+ runners to Chamonix across 8 races, from the kids' Mini-Cross to the 90 km and its 6,000+ m of climbing. New for 2026: the legendary 42 km no longer finishes high up at Planpraz but drops back down to finish in the heart of Chamonix.
Every summer, the Chamonix valley turns into the world capital of trail running. Before the late-August UTMB, it's the Mont-Blanc Marathon that kicks off the season at the end of June: four days of racing, eight formats, and a backdrop few events can match — the needle peaks, the glaciers, and the roof of Western Europe behind it all. Whether you're chasing your first trail or you've been running for ten years, there's a start line for you.
Here's what to know about the 2026 edition, what's changing this year, and how to pick your race.
A trail festival, eight races, one backdrop
The Mont-Blanc Marathon isn't a race — it's a festival. Across its competition days (June 25-28, 2026), the organisers line up eight events that together welcome more than 10,000 runners from around the world: the 90 km, the 42 km (the original "marathon"), the 23 km, the 10 km, the Vertical Kilometre, the Duo étoilé, the Young Race Marathon for juniors and the Mini-Cross for kids.
That range is the event's true signature. Where many big races speak only to seasoned ultra runners, Mont-Blanc lets the first-timer on the 10 km share the valley with the specialist tackling the 90 km. Everyone runs in the same scenery, on the same balconies above the valley.
What's changing in 2026: the marathon comes back down to Chamonix
This is THE news of the year. Since its creation in 2003, the 42 km of the Mont-Blanc Marathon crossed its finish line at altitude, in Planpraz (around 2,000 m), after a brutal final climb. In 2026, that iconic finish is gone: the race now ends in the heart of Chamonix, at Place du Triangle de l'Amitié.
The change is far from cosmetic. Finishing in town means crossing the line surrounded by crowds in the buzz of the centre, rather than on a high-altitude shelf at the foot of the cable cars. The race profile shifts too: after the high point, runners tip down toward the valley for a final descent into Chamonix. If you've run the event "the old way," expect a different feel over the closing kilometres.
The 90 km: the queen of the festival
The 90 km du Mont-Blanc is the big sibling. With more than 6,000 m of positive elevation gain, it's a demanding ultra-trail that loops around the entire Chamonix valley. The start is given on Friday, June 26, from Place du Triangle de l'Amitié, and the course attacks straight away with a long climb toward Le Brévent, one of its high points.
A night start, snowfields still lingering up high, sections averaging between 2,000 and 2,500 m: the 90 km ticks every box of a true high-mountain ultra. It's not a race to start out on, but it's a credible season goal for a trail runner who has already finished shorter formats and wants a taste of the high mountains.
The 42 km: the star trail-marathon
If one event embodies the festival, it's the 42 km, the "Marathon" that gave the whole gathering its name. With roughly 2,540 m of climbing, it's one of the absolute classics of world trail running and a stop on the Golden Trail World Series, the circuit that gathers the international elite of fast, short trail.
The route strings together balconies and single-track above the valley, passes the Charlanon alpine pasture (around the 35 km mark, high point near 2,540 m, facing Mont-Blanc) before — new for 2026 — dropping toward Chamonix. It's a marathon, but nothing like a road marathon: here the clock counts in hours and every metre of climb is earned. For many runners, it's the race of a lifetime.
→ Find and save the Mont-Blanc Marathon in BPMoov to keep every detail of the race at your fingertips and miss nothing.
23 km, 10 km, Vertical Kilometre: where to start
Not (yet) ready for 42 or 90 km? The festival has you covered.
The 10 km is the most accessible event, with modest elevation (around 325 m of gain) — but don't be fooled: a few short, sharp climbs and technical single-track descents are a reminder that this is trail, not a flat road. It's an excellent first taste of the format.
The 23 km is the step up: long enough for a real mountain adventure, short enough to stay within reach with serious preparation. The Vertical Kilometre is a beast of its own: 1,000 m of climbing as fast as possible over a very short distance. Brutal, spectacular, and perfect for anyone who'd rather suffer fast than long.
The smart move: pick the distance that matches your current fitness, not your dreams. If you're new to trail, our guide to preparing (and finishing) your first trail run will help you aim right.
How to prepare (and how to get there)
Racing in Chamonix isn't like racing around the corner. A few practical points:
- Altitude and terrain change everything. Get used to long climbs and technical descents, and train on elevation if you live on the flat. Strength and specific endurance matter more than raw speed.
- Gear counts: proper trail shoes, and for the long formats a hydration pack with the mandatory kit (waterproof jacket, water reserve, etc.). Our GPS watch and hydration vest guide sorts it out.
- Logistics: Chamonix is easy to reach by train and shuttle, and the organisers offer free transport for registered runners. Book accommodation early — the whole valley fills up at the end of June.
Bibs for Chamonix's big races go fast. Save the event you're eyeing in BPMoov to get an alert as soon as registration opens (or reopens) so you don't miss the window.
The bottom line
The Mont-Blanc Marathon 2026 is four days of trail celebration at the foot of the roof of Europe, eight formats for every level, and a brand-new in-town finish for the marathon. Whether you come to grab your first bib on the 10 km or to line up for the 90 km, it's one of the finest playgrounds out there.
BPMoov brings together road and trail race registrations across France and Europe — 2,000+ events listed, free, on iOS and Android. → Download the app to find your next race and keep an eye on it.
FAQ
When is the Mont-Blanc Marathon 2026?
The Mont-Blanc Marathon 2026 takes place from June 25 to 28 in Chamonix, in the French Haute-Savoie. The eight events are spread across several competition days. The 90 km, the longest race, starts on Friday, June 26 from Place du Triangle de l'Amitié in central Chamonix.
What distances are on offer?
The event offers eight formats: the 90 km, the 42 km (the "marathon"), the 23 km, the 10 km, the Vertical Kilometre, the Duo étoilé, the Young Race Marathon for juniors and the Mini-Cross for kids. They range from an entry-level race to a major high-mountain ultra, welcoming every level.
What's changing in 2026?
The main change concerns the 42 km. Since 2003 it finished at altitude in Planpraz (around 2,000 m). In 2026 the finish drops to the heart of Chamonix, at Place du Triangle de l'Amitié. The closing kilometres become a descent into town rather than a final climb.
Is the Mont-Blanc Marathon beginner-friendly?
Yes, as long as you pick the right format. The 10 km (around 325 m of climbing) is an excellent first trail, even with a few technical sections. The 42 km and 90 km, however, demand real mountain experience and specific preparation. Aim for the distance that matches your current level.
Is the 42 km part of the Golden Trail World Series?
Yes. The 42 km of the Mont-Blanc Marathon, with its ~2,540 m of positive elevation gain, is one stop on the Golden Trail World Series, the international circuit that gathers the world's best fast, short trail specialists. It's one of the most competitive races on the calendar.
How do I register and follow race info?
Registration is handled through the official organisation, and bibs for the marquee formats sell out fast. To avoid missing the registration opening and to keep every detail of an event at hand, you can save the race in the BPMoov app, which centralises road and trail races across France and Europe.