It's steep, it's sustained, it's gnarly... it's the Avalanche NW Couloir. Otherwise known as the "Vent Shaft", this ski-mountaineering classic is a beast of a line that requires crossing a deep bergschrund, scaling a 50°+ slope and skiing a convoluted couloir. The technicality of the route is easier to swallow when considering the easy access with no more than 10km of distance. In our case, we opted for a mini traverse from the NRC (Mortar) parking to the Illecillewaet parking.

Starting at the NRC Parking Lot below the Macdonald West Shoulder, we climbed the wide, snaking gully to the base of the alpine bowl below NRC Col. From there, we climbed the rocky, wind-scoured slope to the col. You'll get a pretty amazing view of Mt Macdonald to the east. We donned our glacier harnesses and skinned up the Avalanche North Glacier. Keep in mind the bergschrunds and crevasses along the way. It might be worth roping up depending on snowpack conditions. We then gained the ramp into the Avalanche NW Couloir and crossed a large bergschrund that usually gets filled in by mid-winter. Next up is a steep, 50-degree bootpack to the top of the couloir. Ice axe and crampons are recommended. At its high point, you'll get a glimpse of the expansive Avalanche and Eagle Glaciers as well as the NW Ridge of Mt Sir Donald, famous in the mountaineering world.

The descent takes you through a steep upper pitch and then a mellower ( still 40deg) rocky choke that snakes through the terrain and opens up into the Thomas-Kors Bowl below Avalanche Mt. There, you can really open up the throttle and bomb all the way down to the lower pitch of Avalanche Crest. It's a short scoot to the Illecillewaet Parking Lot where you can carpool back to the NRC lot.