Large natural wind slab on Iceberg Peak, near Cooke

From obs: "... an avalanche we saw out by Goose Lake yesterday (3/27)... we are pretty sure this wasn't there at 8am. On the way back (5pm) we noticed this large avalanche on the NE face of Iceberg Peak at about 11,200. It broke naturally in the new snow which was drifted heavily by SW winds (20-40mph all day). It appears to be 3-4' deep at the deepest spots, 600' wide, and ran 750'. There is a small area below the upper crown that stepped down, but tough to tell if that was just snow from the start of this storm. We did not notice any other activity in the area..."