4 - 5
FATMAP difficulty grade
Starting from the summit of one of the most prestigious peaks in the Alps, this 1000 meter line reigns supreme in the Argentiere Basin and is a popular means of ascending the Aiguille Verte for alpinists.
The early history of skiing on Couturier was marred in controversy over who actually made the 'true' first descent.
Serge Cachat-Rosset skied from the summit via a helicopter drop in August of 1973.
Four days later, Anselme Baud and Patrick Vallencant skied the couloir from just underneath the final icecap after having climbed it.
Although the press at the time celebrated Cachat-Rosset's descent and claimed Baud's and Vallencant's wasn't valid, many have later agreed Baud and Vallencant can claim the first real descent by 'fair means'.
Another victim of climate change, the Couturier is likely to never again be skiable without an abseil in the lower 60 degree ice.
The last known descent without abseil was made by Dave Rosenbarger and Arne Backtrom in June 2009 when they caused a stir at the time for making huge gs style turns down the length of the couloir in perfect powder conditions.
It is possible to bypass the unskiable section of the Couturier via the 'Z' route opened up by Vivian Bruchez in April 2013.
This takes a delicate and exposed line through the rocks to looker's right of the actual Couturier.
From the top of the Grand Montets cable car, ski down the very start of the Point du Vue piste before quickly ducking the rope and heading skier's right.
Keep as much height as possible and traverse under the Cordier Couloir until you are past the overhead seracs.
Skin up from here to the bergschrund of the Couturier.
Climb the line and exit right onto the slopes of the 'Calotte' at two thirds height.
From here it is less steep to the summit of the Aiguille Verte but there are sometimes some crevasses and small serac bulges to negotiate.
Ski back down the same way and down to the Argentiere Glacier.