Thunder Mountain, ski descent of west face. This 2,000' face is prominent on the flight to Kahiltna Base. On April 25 Andrew McLean and I gained the upper glacier by traversing in from the west above a steep narrow icefall. After skinning across the bergshrund we cramponed up and into a couloir on the left side of the face. It ended on a knife-edged corniced ridge. On belay, I looked over into the Thunder Glacier cirque and at the 150 yards of tiptoeing to get to the West Summit Plateau. We skied. Snow conditions and position were fantastic. A K2 Cessna flew by, wagging his wings. In retrospect, to gain the plateau we should have veered up and right at two-thirds height, maybe avoiding the fall line of the humungous cornice.