Should conditions be right, the north couloir on Cathedral Mountain is an excellent but advanced descent with tons of fall-line skiing. It’s an hourglass like route with a 1-2 meters wide choke and a frozen waterfall that usually requires rappelling.
Access: Just East of Cathedral Crags, after skiing the exposed ridge from the summit and onto the glacier, you’ll find a large bowl that funnels into a narrow couloir. Mid-way down the couloir is a 1-10 meters tall waterfall. There is a bolted rappel station (skiers left). After your rappel, the route is obvious and it’s all fall-line fun skiing. You’ll eventually have to cross a set of train tracks before reaching the road.
The exit of this route is about 2km west of the the Lake O’Hara parking lot. Either drop a vehicle off in the morning, or hitch a ride back up.