The Swiss Irontrail 55km (T55) is an alpine point-to-point race held annually in the Val Surses of Canton Graubünden, Switzerland. Starting in Savognin and finishing in Bivio, the route crosses Parc Ela — Switzerland's largest nature park — via the Fuorcla digl Leget, Pass Lunghin, and the ancient Septimerpass. Terrain ranges from alpine meadows and mountain lakes to scree fields and sustained ridgeline running above the treeline. Pass Lunghin is one of Europe's most remarkable hydrological divides: the only point in the Alps from which water drains simultaneously to the Rhine (North Sea), the Danube (Black Sea), and the Po (Adriatic).
With 4,199m D+ over 55km (76.3m per km), the T55 ranks 30th of 390 European ultras for vertical density. Percent-flat terrain ranks 35th of 390: among the least-flat 9% of all European ultras in the database. The Swiss Irontrail series was first established in 2012; the current Savognin-Bivio format runs annually since 2023. Time limit: 16 hours. Entry in CHF via Datasport; an additional administration fee may apply. Nearest airport: Zürich ZRH, 2.5 to 3.5 hours from Savognin; a car is recommended.