I've done this route twice. In 2010 I did this route in June and we had a lot of rocks flying down the slope like missiles. The snow was soft and we could easily kick in steps.
2018- Not a lot of rockfall, although one of my companions was hit with a small golf ball sized rock. We did however have a lot of ice which made the conditions pretty sketchy in a couple of spots. I could not bury the shaft of my axe even an inch and used the axe head for belay.
My take on this route is that it can be fairly straightforward or very sketchy depending on conditions. Go prepared for anything.
The steady stream of small rocks was a bit unnerving. Where the coulouir splits and the left (main) couloir funnels down, I decided to head right, since less stuff seemed to be coming from that direction. After climbing a short ice step, a mixture of rock, ice, and snow led to the cornice just north of where the Grunge would have topped out. Though I knocked plenty of garbage off some rock ledges, I was not bombed at all. Fun stuff!
5/16/2011- An amazing Route!
May 16, 2011 -- Enjoy this so much last year went and did it again this year. This time we started at Mutual Dell, when west on the Timpanokee road and up the coulior above Rock Canyon, then up the Grunge.
June 15, 2010 -- After getting rained out the week before I was lucky enough to make it back and have the opportunity to climb this fantastic route. Watch out for falling rocks!