Decorps-Perroux Couloir (North Couloir)

Decorps-Perroux Couloir (North Couloir)

Page Type Page Type: Route
Location Lat/Lon: 45.84330°N / 6.90740°E
Additional Information Route Type: Mountaineering, Mixed
Seasons Season: Spring, Summer, Fall, Winter
Additional Information Time Required: Most of a day
Additional Information Difficulty: Alpine D/D+, 60°
Sign the Climber's Log


This is elegant mixed couloir was first climbed by P Decorps and G Perroux in December 1979. It lies directly to the right of the North face, is slightly steeper (average 60°) and less crowded than the popular north face. The route is more regularly in condition than the Gabarrou Pointi route further west.

Getting There

The trek towards la Tour Ronde from the Abri Simmonds bivi hut.The walk-in to la Tour Ronde from the Col du Midi

From the Aiguille du Midi station or the Cosmiques hut head south-east across the Col du Midi. Descend the Glacier du Geant skirting the couloirs of Mont Blanc du Tacul to the right. Continue south past Tacul navigating through crevasses to reach la Tour Ronde in approximately one hour from the Midi Station / Cosmeques hut. The North Couloir is directly to the right of the prominent snow slopes of the north face.

Route Description

The starting point will depend upon how lean the conditions are. Towards the end of summer it may be easier to start the route via a snow funnel to the right of the regular starting point in order to avoid lean blue ice. Having crossed the bergshrund bare left to regain the couloir. This alternative start is not straight-forward as there is a tricky mixed step before the bolted rock that will prove the crux move of the day. Climb the couloir for around five pitches navigating through sections of semi-loose rock and good ice. When I climbed the route late summer there was particularly good ice around the middle pitches. Steepness of the couloir varies between 55 and 70°. Belays lower down are particular precarious due to much of the rocks being loose. Towards the top of the couloir there are two possible finishes. Either bare left to join the north couloir, cross to its left side then descend the South-East Ridge or stay in the couloir for its entirety, descend to the Gervasutti Couloir and down-climb it (45 - 50°). The Gervasutti Couloir can easily be abseiled in to via in-situ pegs and slings from the ridge however its bergshrund can be difficult to cross in the late season. Those wishing to summit la Tour Ronde should opt for the former finish line.

The Decorps-Perroux Route on la Tour RondeDecorps-Perroux Couloir with Variations
Tour Ronde topo. Drawn by Ari...Topo of routes

Essential Gear

Nuts and slings are most useful for this route

Also bring a selection of hexes, pegs and cams



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