Grépon Mer de Glace: A major historic classic in the Mont Blanc massif
Rating D, 800m of difficulty, 1000 metres of ascent
Opened in 1911, this route embodies the spirit of the pioneers of Chamonix mountaineering. Even today, it remains a benchmark ascent for any mountaineer with a passion for granite and great ridge climbs.
The route takes in the south-east slope of the Grépon, and climbs almost 800 metres of walls, cracks, dihedrals and jagged ridges to the summit perched at 3,482m. The route is characterised by its continuity: not extreme, but never easy. There is a wide variety of climbing on this route, from 3 on a tight rope to the famous 5c on the Knubel fissure, considered one of the historic routes in the massif. The route is wild: the rock is poorly equipped, the route complex and the descent long. All of which adds up to a complete adventure.
The approach is from Montenvers to the Envers des Aiguilles hut. After an early start, a walk on the Trélaporte glacier leads to the foot of the south-east face, crossing 2 sometimes tricky rimayes. From the very first pitches, the climb alternates between ledges, dihedrals, passages in open cracks and sculpted slabs, before gradually moving towards aerial ridges. The easy sections require efficient progress.
At the summit, the famous Knubel fissure awaits us, steep and athletic, where the history of mountaineering comes to mind. We arrive at the summit of the Grépon at the foot of the Virgin, with the Chamonix valley in the background, a spectacular viewpoint between the Mer de Glace and the Nantillons glacier.
The descent isn't just a simple return. With a series of abseils, then a de-escalation and the crossing of the steep and crevassed Nantillons glacier, it is a serious second part of the race that tests endurance.
Grépon - Mer de Glace is a great historic ridge race, combining scale, complex route and commitment. It is aimed at solid, fast climbers who are comfortable climbing on granite. A demanding route, to be considered as a milestone in a climber's career.
The ascent of the Grépon Mer de Glace route is graded D, with a key 5c passage. The rest of the route is between III and IV+, often climbed with a tight rope. Good alpine climbing experience is essential to successfully complete this route with a guide.
The whole climb takes a long day. Allow 10 to 12 hours for the climb itself, plus 3 to 5 hours for the descent. Then there's the approach on the first day. If you're too slow, you'll have to sleep on the way back to the Plan de l'Aiguille refuge.
Grépon Mer de Glace is a typical granitic climb: cracks, dihedrals, slabs and ridges. The route combines technical sections with short-rope and tight-rope sections, where efficiency is the key to keeping on schedule.
From the west side, via a series of equipped abseils, then via the de-escalade and the Nantillons glacier. The descent is long, sometimes exposed to rockfalls, over a rugged glacier and still requires vigilance and energy.
The ascent of Grépon Mer de Glace can be envisaged from July to early September, when the glacier access is practicable, there is no snow on the route, the rock is dry and the weather allows you to tackle such a long route without fear of storms.
Live with your guide, from first contact to the summit.
Creative and flexible
A flexible framework for devising the most appropriate itinerary or activity for each day, depending on the group and the conditions.
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