Put in a snowshoe track to access this buttress at the head of seymour creek under north face of north twin sister, this zone is pretty legit. Ice was better than average for washington. Approach took longer than expected and we only did a couple lines on the lower tier at wi3 and wi4. Whole thing probably goes at wi4, maybe 70m tall? Somebody should get out there while they don't have to break fresh trail! 2.5-3 hrs with a trail in place from the gate closure. 4-5 hrs if breaking trail. Looked like decent snow camping next to the creek under the crag.