© Vincent Croce

GR®738 Haute Traversée Belledonne: hiking & nature in Isère

The GR®738 is a 130km route that crosses the entire Belledonne massif, a real Holy Grail for hiking enthusiasts. From glacial lakes to dense forests, from high-altitude passes to tranquil mountain pastures, this demanding alpine route offers the ultimate reward: breathtaking scenery and the satisfaction of an extraordinary adventure. We’re heading out for a few days to experience it ourselves!

Stretching 80 kilometres from north to south, the peaks of the Belledonne range form a majestic natural wall above Grenoble and the Grésivaudan valley, linking Vizille in Isère to Aiguebelle in Savoie.

Seen from afar, the Belledonne massif imposes its alpine and lofty presence, offering a striking contrast with the limestone massifs of the Chartreuse and Vercors.

Although intimidating, the beauty of the Belledonne massif exerts a powerful attraction, inviting adventurers to explore and conquer its imposing peaks.

 

 

From shepherds to trail

Belledonne’s peaks, often explored by locals in just a day or two, now have a dedicated long-distance trail, the GR®738, opened in 2018.

The trail, originally called the “Shepherds’ Path” (Sentier des Bergers), was started 20 years ago by the Fédération des Alpages to link farming and tourism.

Along the route, hikers often come across herds of sheep, making it important to respect the needs of the farmers and share this natural space peacefully.

Good practice in the mountains

© Vincent Croce

“The trails, shaped by thousands of years of pastoral practice, have recently been integrated into various tourist and sporting activities. The idea behind the Shepherds’ Trail (Sentier des Bergers) was to continue to share the history of pastoralism with hikers who cross almost all the sheep pastures in the Belledonne on this route.”

Joseph Paillard Fédération des Alpages

High-altitude mirrors

People often mistakenly translate ‘7 Laux’ as ‘7 lakes’, but this plateau actually has at least 12 lakes set amid the eroded rock. The name comes from the Latin ‘Cælum-i-o’, meaning ‘mountain of heaven’, which aptly describes the breathtaking views before us.

These high-altitude lakes seem to be in perfect balance between the ridges and flower-filled meadows. The waters of the lakes, in varying shades of blue, contrast magnificently with the surrounding rocky landscape, creating a dreamlike scene.

In all, the Belledonne mountain range has more than 70 lakes scattered like hidden treasures along its 120 kilometres of trails.

© Vincent Croce

Car-free hikes

The mountains without a car

Belledonne, like the Chartreuse and Vercors massifs, is easily accessible by public transport. Whether you want to explore the whole area or just part of it, you can take a bus from Grenoble or the Grésivaudan valley to Chamrousse or Le Pleynet to access the GR®738 trail. The bus journey offers breathtaking views of the Belledonne landscape and a refreshing escape from the city. Once the M Tougo 607 bus drops us off at Le Pleynet, the contrast with the streets of Grenoble is spectacular; we are surrounded by green slopes and rushing streams. From the car park, we climb 800 metres to reach the 7 Laux, a series of glacial lakes that alone have made the massif famous.

All car-free hikes

Comfy refuges…

Les 7 Laux is also the name of the hut where we spend the night. Rustic and welcoming, it’s easy to feel at home here. After the climb, we take advantage of the sunny terrace to enjoy a slice of tarte aux myrtilles (wild blueberry tart), while admiring the beauty of the surroundings! In the evening, dinner is served at a fixed time for everyone, and the hikers gather around large communal tables. The menu includes a hearty soup, a croziflette and a creamy dessert – simple but delicious. Hikers share their mountain stories and their plans for the next day. Those who still have some energy left play cards before heading to the communal dormitory. Ten or so refuges dot the route between Isère and Savoie, each offering a rustic and comforting experience, a cosy shelter from the challenges of the mountains.

© Jérémy Tronc

…and intimate bivouacs

During our trip, we noticed that more and more hikers were choosing to bivouac, often near refuges like Les 7 Laux or on the shores of serene lakes. Bivouacking involves camping in a temporary shelter, usually for one night, allowing hikers to immerse themselves in nature. Although this practice requires specific equipment that weighs down your bag, it allows a deeper connection with nature. You can soak up the tranquillity, admire the breathtaking scenery as night falls and gaze up at the starry sky. It is important, however, to follow certain rules, which are essentially common sense: no fires, no swimming, no washing up in streams and no littering.

© Jérémy Tronc

Mineral landscapes

Hiking in the Belledonne also means coming face to face with its rugged terrain and mineral landscapes, both stark and mesmerising in equal measures. After leaving Les 7 Laux and heading south, you’ll be crossing scree, talus, mountain passes and rock bars at an altitude of over 2,400 metres. You’ll discover the steep Col de la Vache, often still covered in snow, the technically demanding Breche de Roche Fendue and the imposing Col de la Mine de Fer, which opens onto a spectacular cirque surrounded by towering walls. These harsh environments heighten your senses and evoke a sense of wonder, reminding you just how small and vulnerable you are. With determination, you move forward, embracing the adventure that lies ahead.

© Vincent Croce

  • 130 km distance

  • 10,000 m of positive ascent

  • 15 refuges or huts along the route

  • 11 days of walking

  • 284 m minimum altitude

  • 2,545 m maximum altitude

Fauna & flora: a rich, preserved treasure

The Haute Traversée de Belledonne offers a unique opportunity to observe the local flora and fauna. The massif serves as a sanctuary for numerous species. Along the way, we often came across ibex and chamois, gracefully agile and quick on the steep slopes. The high mountain flora, well adapted to the difficult conditions, is an astonishing testimony to nature’s resilience in this rugged environment.

It’s an adventure – one of the wildest in the French Alps.

© Jérémy Tronc

A unique human experience

Beyond the landscapes, the Haute Traversée de Belledonne offers a profound human adventure. Setting off on this trail means immersing yourself in a different rhythm of life, shaped by the hours of walking and the stages to be completed. Each day is a new discovery, and each pass you cross brings its own surprises and spectacular views. Along the ridges, lakes and summits, you’ll discover the richness and diversity of the Belledonne massif. It’s an adventure, one of the wildest in the French Alps, which, once completed, will leave you with unforgettable memories and an irresistible desire to return. Because Belledonne can’t be discovered in a single crossing, it has to be experienced, contemplated and explored again and again.

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In the Belledonne massif