Carved directly into the cliff face between 1896 and 1898, the Col de la Machine road crosses the Combe Laval natural amphitheatre through a sequence of tunnels and suspended balconies — one of the most spectacular roads in the Vercors.
A technical climb along a balcony road
From Saint-Jean-en-Royans, it’s 12 km for 745 m of elevation gain, averaging 6.2%, with an irregular profile that alternates flat stretches and ramps beyond 13%. The pass tops out at 1,011 m.
A road cut straight into the rock
The road runs through around ten tunnels carved into the limestone and long balcony sections overhanging the Combe Laval amphitheatre, more than 300 m above the valley floor. Originally built to haul timber out of the Forêt de Lente, it remains a remarkable feat of 19th-century engineering.
Getting the ride right
Front and rear lights are useful for getting through the tunnels safely, since visibility drops sharply even in broad daylight. Caution is still needed on the balcony sections that lack any guardrail.
When to go
April to November — the road stays rideable most of the year outside winter freezes, which can leave it slippery in places.
Good to know
Saint-Jean-en-Royans, at the foot of the climb, offers a less crowded way to discover the Vercors than its bigger alpine neighbours, with architectural heritage tied to the region’s timber and forestry history.
