Lac du Vieux-Emosson Bike Climb | Cycling the Swiss Alps

Switzerland Lac du Vieux-Emosson

Lac du Vieux-Emosson Bike Climb - PJAMM Cycling

39.2

PDI

16 mi

DISTANCE

6,137 ft

GAINED

ELEVATION GAINED

6.4 %

AVG. GRADE

AVG. GRADIENT

FULL CLIMB STATS

Page Contributor(s): Ard Oostra, Montreux, Switzerland; Erwan Treguier, Brittany, France

INTRO

Lac du Vieux-Emosson is a demanding reservoir climb in Switzerland's Valais, starting in Vernayaz in the Trient Valley and finishing above 2,200 m at a pair of dams near the French border. The route covers about 16 miles (25.9 km) and gains roughly 6,137 ft (1,871 m) at an overall average of 6.44%, though the real climbing - once the road leaves Finhaut - runs closer to 9-11%.

The road climbs through the historic villages of Salvan, Les Marecottes, and Le Tretien before narrowing above Finhaut into a quiet, tree-lined ascent for roughly 7 km. It tops out at the Col de la Gueulaz and the newer Emosson dam, where Stage 17 of the 2016 Tour de France finished - Ilnur Zakarin won the stage solo while Chris Froome and Richie Porte broke away together on the climb's final, brutally steep kilometer.

From there, the route continues across the Emosson dam and up a narrower, largely unpaved extension to the older Vieux-Emosson dam - a spectacular but demanding final stretch cut into the rock face with short tunnels and no guardrail, averaging 15-16% over its last mile and a half. This extension has a history of multi-year closures, so check current access before counting on reaching the very top.

PLAN YOUR ROUTE

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Lac du Vieux-Emosson averages 6.44% over its full 16-mile length, but that number hides a two-stage profile. The lower approach through the Trient Valley to Finhaut is gentle by comparison, then the road steepens hard once it leaves town: the steepest kilometer averages 16.06%, the steepest half-kilometer 17.13%, and the steepest 100 yards touches 19.66%, almost all of it concentrated in the final push past the Emosson dam toward Vieux-Emosson.

Even the steepest 5-mile stretch still averages 8.68%, which shows how little of the upper climb offers real recovery. With a FIETS score of 11.9, this is one of the more lopsided profiles among PJAMM's Swiss Alps climbs - deceptively moderate on paper, brutal in its closing kilometers.

Roadway: The lower two-thirds of the climb, from Vernayaz through Salvan, Les Marecottes, and Le Tretien to Finhaut and on to the main Emosson dam, is smooth, well-maintained Swiss tarmac the entire way. Past the dam, the short extension to the older Vieux-Emosson dam is a different story - a narrow, largely unpaved lane (roughly 20% dirt and gravel by one rider's account) carved into the rock face with a couple of short tunnels and no guardrail. It's rideable on a road bike with wider tires, but it's a deliberate, technical add-on, not an extension of the smooth road below.

Traffic: Traffic on the main road up from Vernayaz is light and thins out further past Finhaut, where the road narrows into a quiet, tree-lined ascent that locals treat as their own private climb. The final stretch to Vieux-Emosson sees essentially no vehicle traffic - it's too narrow for two cars to pass, and it has been closed to cars outright in past years, though it has stayed open to cyclists and pedestrians when open at all.

Parking: There's a car park at the main Emosson dam (Col de la Gueulaz), where a cafe and the top station of the Emosson mini-funicular from Le Chatelard also sit - a natural turnaround point if you'd rather not tackle the final unpaved stretch to Vieux-Emosson.

Vernayaz and Salvan have basic grocery stores, and Finhaut has a small shop and places to eat - useful last stops, since there's nothing beyond Finhaut until the cafe at the main Emosson dam near the top.

This is a strictly seasonal climb: the road typically opens around mid-May and closes by mid-October depending on snowfall, and it isn't passable at all outside that window. Given the altitude and exposed final kilometers, pack layers even in summer - temperatures above 2,000 m can be dramatically colder than in the valley below.

Before heading out on any cycling adventure check out our Things to Bring on a Cycling Trip and use our interactive check list to ensure you don't forget anything.

Martigny, the nearest rail hub, has bike shops and full services, and makes a good base for exploring other Valais classics like the Col de la Forclaz and the Grand St. Bernard. If you'd rather skip the lower valley miles, the Chatelard-Vallorcine rail line and the Emosson mini-funicular from Le Chatelard both offer ways to shortcut higher up the mountain.

The main dam was the mountaintop finish of Stage 17 of the 2016 Tour de France, where Ilnur Zakarin won solo as Chris Froome extended his overall lead - worth knowing if you want to trace the finale on the final kilometer past the dam. For other climbs nearby, see our Routes in the Area tool.