Lac de la Sagne

Lac de la Sagne is a mountain lake in the commune of Allemond, in the Isère department of the Auvergne-Rhône-Alpes region of France. Sitting at roughly 2,065 metres above sea level, it belongs to the Belledonne massif, in the group of high-altitude lakes known as the Sept Laux — a name meaning "seven lakes" even though the group actually counts ten, including Lac de la Corne, Lac Agnelin, Lac Blanc, Lac Noir and Lac Carré. Lac de la Sagne is typically the first lake reached on the classic approach from the Eau d'Olle valley, and its bare, rocky basin framed by Belledonne peaks draws hikers throughout the warmer months.

How do you get there?

The usual starting point is Le Rivier d'Allemond, a hamlet within the commune of Allemond. From there a road continues roughly 2 km further up the valley to the trailhead, where the path branches off toward the Sept Laux basin and climbs in tight switchbacks. The round trip generally runs 9–10 km with close to 900 metres of elevation gain, making it a full but achievable day hike for anyone in reasonable shape. The final stretch crosses loose, rocky ground and gets noticeably steeper, so sturdy boots and trekking poles are worth bringing.

When is the best time to hike?

The hiking season around the Sept Laux runs broadly from April to October. Outside that window, the higher sections of the trail can still be covered in snow or ice, and reaching the lake may require winter gear and experience. Conditions are most reliable in summer, once snow has cleared from the upper valley and the approach trail is fully walkable.

What wildlife can you expect along the way?

The Eau d'Olle valley and the Sept Laux area are known for their alpine wildlife. Chamois are a regular sight, and ibex — reintroduced to the area in the 1980s by hunters and EDF around the time the nearby Grand'Maison dam was built — can also be spotted on the open, rocky slopes surrounding the lakes. Early morning is generally the best time to catch sight of them, when the trail is quiet.

What's the wider setting?

Allemond stretches across the upper Eau d'Olle valley, between the Belledonne massif and the Grandes Rousses range, close to the well-known Vaujany and Alpe d'Huez ski resorts. While Lac de la Sagne itself sits on the Belledonne side of the valley, the surrounding area combines genuinely wild, high-altitude terrain with easy access to major mountain resorts — a combination that makes it a convenient base for hikers looking to pair a quiet lake outing with the amenities of a larger ski town.

Frequently asked questions

Where exactly is Lac de la Sagne? In the commune of Allemond, Isère department, within the Belledonne massif, as part of the Sept Laux group of lakes, at an altitude of around 2,065 metres.

Where does the hike start? Most hikers begin at Le Rivier d'Allemond, from where a marked trail leads up into the Sept Laux basin.

How long is the hike to the lake? The round trip is usually around 9–10 km with roughly 900 metres of elevation gain — a full day out for hikers with a reasonable level of fitness.

Is the trail difficult? Yes, it's generally rated as demanding. The final approach runs over rocky, occasionally steep ground, so it's worth allowing plenty of time and packing proper footwear.

What's the best season to visit? Broadly April through October, though the trail's upper sections are usually only fully clear of snow during the summer months.

Is wildlife visible around the lake? Yes — chamois are common, and ibex reintroduced in the 1980s can also be seen in the surrounding Eau d'Olle valley.

Is Lac de la Sagne the only lake in the area? No. It belongs to the Sept Laux group, which actually comprises ten lakes, including Lac de la Corne, Lac Agnelin, Lac Blanc and Lac Noir, so several can often be combined into a single hike.