At approximately 12:35 PM at the ski area boundary, my ski partner and I came across a fresh D1 slab avalanche on the same sun crust layer about 50 ft wide. We skied beyond this avalanche which we later assumed was sympathetically triggered by the avalanche that is the subject of this report. When we crossed through some dense trees we saw the larger slope on the other side of the trees had slid, and we could see the victim partially buried and pinned in a treewell with only his helmet visible. He was calling for help. He had been skiing with a partner who was safely stopped below. Once we communicated with both of them and ascertained there were no other potential victims, we began to extricate the skier from the treewell--this took two of us approximately 10 minutes of digging with avy shovels to remove the snow and disentangle the victim from the trees. He sustained no injuries, lost a ski in the slide, and was able to ski back into the ski area and down to Southern Cross on one ski.
The partially buried skier reported to us that he and his friend had hiked the ridge to the ski area boundary sign and dropped in skier's right of the sign. They were not the first skiers on the slope, as there were several other older tracks entering the crown and slide area.