This couloir is a relatively popular objective that is highly visible from The Remarkables Ski Area and towers just out of bounds. It is the couloir that sits between Double Cone and Single Cone and has multiple approach options. The initial pinch is narrow and steep, and depending on the snowpack may or may not be skiable. Usually there is enough snow that the pinch can also be avoided by going lookers left down the north face of single cone and then rejoining the couloir as it widens up and mellows out down to Lake Alta.
There are two main approach options, one is up the gut of the couloir and the other is the mountaineering route over the back and summit of Single Cone. The skin and bootpack up the gut is pretty straightforward but for those that want some different views, want the option to not skin, and/or want to shorten the approach by starting at the top of the Curvey Basin chairlift, the mountaineering route to the top of Single Cone is also an option. To approach up the gut, either skin up under the Alta chairlift and turn right at the top towards the lake or ride the Curvey Charilift and ski down to Lake Alta. Once you cross the lake you can skin up the lower portion of the couloir where it is mellow and wide open. About halfway up you'll want to transition to crampons and make sure you have an ice axe as the top of the couloir gets quite steep and possibly rocky. To approach over the back either skin up under the Curvey Basin Chairlift or ride the lift, from there you'll bootpack or skin up to the knoll out of the gate on your right. Then you will head across the flats to the south ridge of Single cone and either skin or bootpack up to the ridge. Once on the ridge if you have not transitioned to crampons already you should do so now. Before the summit of Single Cone there is a brief, near vertical climb where you will need crampons and an ice axe. This is an extremely high consequence zone where any fall will result in severe bodily harm or death so watch your step. After this section it's only another 50 feet to the top.
The initial pinch
The Grand Couloir is a great, relatively short objective that is easy to access from The Remarkables Ski area. As New Zealand tends to have a spring-like snow pack all season long and this objective faces North/Northeast (the sunny side when you're down under) it's important to be at the summit no later than noon. The more popular approach is up the gut as it is straightforward and allows you to asses the snowpack as you climb. The views from the top of Single Cone are absolutely breathtaking, so definitely don't dip out before the summit if you go up the gut. If you do choose the mountaineering route you will most likely have company on the uphill from local guided mountaineering tours. Other than the pinch near the top this is a nice, wide, mellow couloir that's a really fun, short spring mission!
