Destinations · France
Trail Running the Mont Blanc Massif from Chamonix: The Complete Guide
Tiia Monto / CC BY-SA 3.0 via Wikimedia Commons
Chamonix is the spiritual home of alpine trail running. This is the valley of the UTMB, ringed by the Mont Blanc massif, with a network of balcony trails, cols and summits that runners travel from all over the world to tick off. Whether you want a gentle valley loop or a lung-busting day linking cols at altitude, the Chamonix side of Mont Blanc delivers.
The classic routes
Start with the Petit Balcon for an easy valley-level run through the forest. Step up to the Grand Balcon Sud, the high traverse facing the Mont Blanc massif, with the Aiguille du Midi and the glaciers straight across the valley. Strong runners link cols on the Tour du Mont Blanc trail, take on the Aiguillette des Posettes, or run up to the Lac Blanc for one of the great mountain-lake views in the Alps.
Seasons and altitude
The high trails clear from June and stay good through October, with September a favourite for stable weather and thinner crowds. Remember you are running at altitude on exposed mountain terrain: weather turns fast, afternoons can bring storms, and the descents are steep and technical. Carry layers, water and a phone, and start early.
When a guide helps
You can run most of the marked balcony and valley trails self-guided. A local running guide is worth it if you want to link higher, less-travelled routes, learn the terrain safely, or run cols and passes where navigation and mountain judgement matter.
Frequently asked questions
Do I need to be an experienced runner?
There are gentle valley routes for anyone, but the balcony and col routes are for fit, experienced trail runners comfortable on steep, technical ground.
When is the best time?
June to October, with September offering the most stable weather and quietest trails.
Can I run without a guide?
Yes, on the marked trails. A guide adds a lot for higher, linked routes and for learning the terrain quickly and safely.
