This couloir may not yet have been climbed all the way to the summit of Robson. If anyone knows anything about it, then please post a comment with any details.
Winter, 1964, Leif-Norman Patterson and Les Wilson skied up the snow-covered brush of the unnamed creek below the south face. They did not climb the couloir. Instead they climbed a snow spur up to the Resplendent-Robson Col, bagged Resplendent, and skied out the Berg Lake Trail.
September of 1994, Greg Horne and Les Wilson, from the Forster Hut, approached via the yellow ledges, crossed the couloir, and then traversed up right to the Patterson-Wilson spur, then over col and down Robson Glacier in dangerous storm, no summit either. (Horn, CAJ, 1995)
Perhaps during couloir climbing season (spring), with snow deep enough to ski over the brush, the rocks of the Dome plastered in place, the couloir scoured by avalanches, this could be a fast way up to the base of the Kain Face.
The couloir may still be unclimbed.
Could rap anchors be hammered into the rock walls?
Is it skiable/rideable?