5 - 6
FATMAP difficulty grade
The normal start for the Haute Route takes the lift to the summit of Les Grands Montets, skiing from the Col des Grands Montets.
Take crevasse rescue kit in your group and have recently practised prussiking and crevasse rescue.
A minimum would be 30m ropes x 2 in the group, and each person to carry a long sling, 3 screwgate karabiners, prussiks and an ice screw.
Mechanical devices such as minitraxion, tibloc and ropeman can make it a lot easier. Start with a defensive side slip down the initial section before skiing down the Glacier des Rognons run, head to the right of the conspicuous rock rognon.
During the ski touring season you can expect a well covered glacier but the crevasse zones are ever present on this serious glacier run.
Reach the flatter Argentiere Glacier and stick to the tracks leading down on the glaciers left bank, while watching out for the odd crevasse on the right hand side.
Just after exiting the main crevasse zone head right across the glacier, aiming to exit on the opposite side.
This section is getting steeper from season to season, and may require you to boot for a short section before climbing steadily to the ski depot at the base of the Col du Passon, after making a rising traverse up the final slopes. Some mountaineering is required here to climb the couloir above.
Whether you choose to climb roped or unroped, the climb is relatively short, and you soon reach the Col du Passon.
Here another transition to skiing allows you to take in the views once more.
The initial section can be steep on the other side but soon reduces in gradient allowing you to scoot over the glacier under the North Face of the Aiguille du Chardonnet.
An easy angled section follows before the need to climb gently once again to reach the Col Superior du Tour.
A small section of booting is usually required through the rocks at the top but is much easier than before.
An alternative route here is to cross the Col du Tour, which often involves a steep climb at the left hand side as the glacier has receded.
Careful choice of line here should allow you to ski all the way over the Plateau du Trient and onwards towards the Cabane du Trient.
A short ascent remains to the friendly Cabane du Trient, where you can enjoy a well earned rest.