Monterosa Walserwaeg by UTMB 120km ('Les sentiers des Valdôtains') is a high-alpine trail race held July 17–19, 2026, starting from Aosta and running through the Lys Valley of the Aosta Valley, Italy — between the Matterhorn and Monte Rosa massifs — passing through Walser mountain villages and finishing in Gressoney-La-Trinité.
The course covers 120km with 7,400m of gain (61.7 m/km) — in the same elite tier as Mestia Ultra in the Caucasus. At 15.2% distance-weighted average uphill gradient (top 1–2% of the DTR database), with 15.1 km of 20%+ terrain and a 38.6% DNF rate in 2025 this is one of the most demanding 120km ultras in the database.
Entry costs €240 plus the UTMB 8% administration fee (€259 effective / €2.16/km). Turin (TRN) is 1.5–3.5 hours by road — IS FAR. Previous editions have sold out; 2026 registration was still open as of research date. It suits experienced mountain ultra runners who want UTMB 100M qualifying points in the shadow of Monte Rosa.