Iron Mountain

Went for a quick tour before sunset intending to ride a short NW aspect around 7700ft. No signs of instability until I reached the summit plateu at the old ski lift above hwy 88. While I was standing still, my partner triggered a collapse that made me fall vertically 1-2" and made the loudest whumph I've heard personally. This collapse seemed to be limited to the entirety of the summit plateu (approximately 100x200ft). Shovel shears were releasing easily with 3-5 taps at the new/old snow surface interface, however we made a safe guess that the collapse was likely much deeper, and we rode back to the car along the old ski cut.

Quick report