Lac Blanc

Lac Blanc is a glacial lake in the commune of Huez, in the Isère department of the Auvergne-Rhône-Alpes region of France. Sitting in the Grandes Rousses massif at roughly 2,525-2,528 metres above sea level, it is one of the best-known hiking destinations around the Alpe d'Huez ski resort. The lake is protected as a classified site (site classé) within Isère because of its landscape value.

Where is Lac Blanc and how do you get there?

The lake stretches about 900 metres in length and 250 metres in width, covering a surface of roughly 13 hectares. It sits below Pic Blanc (also known as Pic du Lac-Blanc), the peak to its northeast that gave the lake its name. Water drains from the lake through the small Rif Brillant stream.

Access runs across the same slopes used by the ski resort in winter, which turn into walking paths once the snow clears. The two most commonly used approaches come from the Tunnel des Grandes-Rousses to the northeast and from the Dôme des Petites Rousses to the northwest. The classic route starts directly from Alpe d'Huez and is a demanding, multi-hour climb with a substantial elevation gain, so it is worth setting aside a full day and starting early. Some visitors shorten the ascent by riding the lifts that operate during the summer season, cutting out the steepest section of the walk.

What will you see at the lake?

Lac Blanc sits at the heart of the Grandes Rousses massif and serves as a viewpoint over the Alpe d'Huez resort and the surrounding ridgelines. The contrast between the blue-turquoise water and the bare, high-altitude rock around it is the main draw for hikers and mountain bikers during the summer months. Several other lakes lie nearby, forming a well-known circuit of lakes around Alpe d'Huez, which means a visit to Lac Blanc can easily be extended into a longer loop that takes in multiple viewpoints in a single outing.

Because the lake sits above 2,500 metres, it stays frozen or snow-bound for much of the year, and the paths around it are realistically only fully walkable during summer.

When is the best time to visit?

Summer, roughly from June to September, is the best window for a hike to Lac Blanc: the snow has usually cleared from the paths by then, and the days are long enough for a multi-hour climb and a safe return. In spring and early summer, patches of snow can still linger at the lake's altitude, which makes the walk longer and more demanding, while in autumn the weather high in the Grandes Rousses can change quickly, so it is worth checking the forecast shortly before setting out. In winter, the ground around the lake becomes part of the snow-covered Alpe d'Huez ski area and is not intended for hiking.

Frequently Asked Questions

How high up is Lac Blanc? The lake sits at around 2,525-2,528 metres above sea level, in the Grandes Rousses massif above Alpe d'Huez.

How big is the lake? Lac Blanc is roughly 900 metres long and 250 metres wide, with a surface area of about 13 hectares.

Where does the lake's name come from? It takes its name from the neighbouring peak, Pic Blanc (Pic du Lac-Blanc), which rises above the lake to the northeast.

Can you reach the lake without a full-day hike? Yes — during the summer season, part of the ascent can be shortened by using the operating lifts, though the classic walking route from Alpe d'Huez remains a demanding, multi-hour outing.