12 km
6:40 /km
Lower valley loop.
Alpine, technical, high vertical.
Trail half within the Mont Blanc massif — sister event to the UTMB family.
Because earned altitude rewrites what you thought the day could hold.
Granite watches quietly. Every switchback earns its view.
A physical profile — respect the ascents; let the descents restore the breath.
Warm to hot. Early start, shade-line and salt matter — carry more water than you think you need.
A warm regional start — clubs in matching kit, coffee vans, a local mayor with a microphone. Human-scale and unhurried.
Loyal, knowledgeable crowd at trail-heads and villages. Deep silence between — the wind and your breath as company.
A quieter stretch usually opens up between km 7 and km 13 — an interior mile to return to yourself before the final push.
Sealed city tarmac — closed to traffic on race day
Elevation and mixed surfaces make this a physical line. Handcycles only with a support team; sturdy adaptive strollers on the flatter opening kilometres.
Cold-stream soak, alpine tea, early bed.


6:40 /km
Lower valley loop.
7:00 /km
River-flat shuffle.
5:20 /km
Push the climb, float the descent.
Soft, restorative · step-free, wheelchair friendly
Only forward · run with the land
Forest-grounded · deeper trails, longer days
Long, open lines · quiet lanes, long horizons
Shared maps · shared GPX engine · shared Soul Signature language. Whichever door you enter, the craft standard is the same.