The Grimselpass, at 2,164 m in the Bernese Oberland, links the cantons of Bern and Valais via a high-mountain road that runs past hydroelectric dams and reservoirs, at the gateway to the Rhône glacier.
A climb between dam lakes and high mountains
From Innertkirchen, the road climbs about 25.6 km for 1,500 m of elevation gain, averaging around 5.9% — a gradient that steepens in stages as the scenery rises above the Aare valley. The route runs alongside the Grimsel reservoir, built by the Kraftwerke Oberhasli dams, before reaching a bare, rocky pass with views over the first foothills of the Rhône glacier on the Valais side.
Getting the ride right
A compact or triple crankset is still useful on the more sustained sections, particularly around Guttannen. Weather in the Swiss high mountains can change quickly: warm layers are recommended for the descent on the Gletsch side, often cooler and windier than the Bernese side.
When to go
June to September, as the road stays closed by snow the rest of the year at this altitude. July and August offer the best conditions, with the option to link straight into the Furka Pass from Gletsch for riders after a big two-pass day.
Good to know
Innertkirchen and Meiringen, in the Aare valley, offer a good choice of accommodation, with convenient access to Interlaken for a stay combining this climb with other classics of the Bernese Oberland.
