Few events capture the romance of European mountain running quite like the Marathon du Mont-Blanc, and the 2026 edition returns to Chamonix from Thursday 25 to Sunday 28 June. Held each year at the foot of the highest peak in the Alps, the festival has grown from a single mountain marathon into a sprawling programme of races spanning 10 to 90 kilometres, drawing elite skyrunners and weekend adventurers to the same start lines beneath the glaciers.
The flagship 42km remains the event's mythical centrepiece, a punishing tour that climbs to the Vallorcine ridge and the high balconies above the valley before delivering its trademark finish at the Plan de l'Aiguille. For the most seasoned competitors, the 90km ultra is the headline test, carrying runners across 6,330 metres of ascent through the Aiguilles Rouges, over the Col des Posettes and across a string of high alpine passes before the long descent back into Chamonix. It is a route that rewards climbing strength and sure footing in equal measure.
The shorter distances are no afterthought. The 23km is one of the oldest races in the calendar and serves as a fierce, fast-moving contest in its own right, while the 10km and the vertical events give newcomers and specialists a way into the festival without committing to a full day in the mountains. Children take part in the Mini Cross, and teams tackle the Duo etoile night run under the stars, a reminder that the weekend is built around participation as much as elite competition.
Race day in Chamonix blends serious competition with genuine festival energy. Thousands of spectators line the streets of the valley town, cowbells echo from the hillsides and music carries the mountain spirit through the crowds. The Trail Camp expo runs across Friday 26 and Saturday 27 June, where runners collect race numbers and browse the latest kit, and the town's cafe terraces fill with the particular nervous anticipation that precedes a big day at altitude.
Coming a fortnight before the summer's marquee ultras, the Marathon du Mont-Blanc occupies a valuable slot in the racing calendar, offering early-season form for those building towards the bigger objectives later in the year. With its mix of accessible distances and unforgiving high-mountain routes, it remains one of the most coveted weekends in the trail running year, and the 2026 edition looks set to continue that tradition.