Argentiere, head for the Grands Montets lift, buy alpinist ticket to Grands Montets station, 23.50 euro for aller-retour; 18 euro for aller (March 2005).
As you walk down the steps of the Grands Montets Station, the col to the left (ENE) toward the Argentiere Glacier is the direction you will descend. Once down the initial slope (25 meters), stay to the right, hugging the cliff-face as you pass under the rope that cordons off the area with a sign warning of crevasses and avalanche danger. Continue along, staying high, for about 400 meters. That should put you in front of Chevalier Couloir.
A year ago, Noah and I made the mistake of not taking snowshoes or skis (per OHM advice "not necessary") and paid the price...a tiring, post-holing, slog that wore us out and ate up the time we had well before we reached the bergshrund for the route. This year, touring skis had me at the start of the climb in 3 minutes, my partner had snowshoes but did not have to employ them and arrived 10 minutes later...BSM applies.
As Tom points out on the Main Page, crossing the bergshrund can be the crux of the climb; it was for us. Having approached from the col, we stayed high up on the slope and crossed the bergshrund on the left-hand side of the couloir. Traversed back towards the middle of the couloir; placed ice screw after hacking away a significant amount of snow to get to a solid ice layer and simu-climbed till about the half-way point where we exchanged leads using the rock outcrop on the right-hand side where the couloir narrows as a belay. Continued up, staying close to the right hand side, for approxiamately 80 meters (simu-climbing) before setting up belay on perfect, slingable rock on left hand side. Changed leads again and the last 30-40 meters was easily covered to gain the snow ridge. You can follow it up 40 meters to gain the summit or you can rappell off from the rocks directly below the snow ridge that have in situ rappell rings (they are on the front side and can not be seen from the snow ridge). One 50-60 meter rappell will take you clear of the bergshrund on the north face after which we were able to amble down to the station.
Snow conditions were ok. Styrofoam snow on the lower portion immediately after clearing the bergshrund, together with a small, 5 meter section of hard, surface ice as we turned up the middle of the couloir. Ascending, the snow became more powdery with few positive sticks, requiring piolet panne for the remainder of the climb.
Do not be seduced into thinking rocks will provide you with a good stance to catch your breath or belay from. The snow in the immediate vicinity of rocks may be only a hollow, top-crust as the warmth from the rocks melts the lower snow away creating a cavity.
2 ice axes
2 22cm ice crews
two 50-60 meter ropes (esp. for rappell off north face on descent)
small to mid-sized nuts
couple of carabiners
snowshoes/skis for approach
Avalanche rating on day of climb (Mar. 10) was 2.
Saw no avalanche or falling rocks anywhere for the duration of climb.
Temp posted on info board at top of Grands Montets lift: -12 C
Clear skies, with little wind and a lot of sun.
No other parties on route.
Cost as a guided route: 232 euro.