Triggered remotely after a skier was about 50 feet below the highest crown. He got carried slightly and then traversed safely to skiers right. I'm not sure if realized when he saw the slide or heard us yelling. The slide broke anywhere from 12" to 24" at the top and along the side about 12" halfway down the gully as well. It ran out down into another gully and may have caught others at the bottom as there was more traffic there (almost to the cat road). Our group noticed cracking and whumphing halfway down on the same shot on our first lap. Our group decided to go slightly south to Christmas Tree but a solo skier dropped Stonecrusher as we watched with no issues. This was about 1 hour before the second skier (also solo) triggered the slide. The second skier was notified of our findings from earlier. See photos and video for more details.
Alta Ski Lifts is not open for the season yet.
![](https://utahavalanchecenter.org/sites/default/files/styles/observation_image/public/archive/avalanche/avalanchestonecrusheralta_11132011-2.jpg?itok=irSsAHjU)
![](https://utahavalanchecenter.org/sites/default/files/styles/observation_image/public/archive/avalanche/avalanchestonecrusheralta_11132011-3.jpg?itok=RDVT_64c)
![](https://utahavalanchecenter.org/sites/default/files/styles/observation_image/public/archive/avalanche/avalanchestonecrusheralta_11132011-4.jpg?itok=i91oYRAE)
![](https://utahavalanchecenter.org/sites/default/files/styles/observation_image/public/archive/avalanche/avalanchestonecrusheralta_11132011.jpg?itok=FatGwJjT)
![](https://utahavalanchecenter.org/sites/default/files/styles/observation_image/public/archive/avalanche/altabackcountrygunsightdiagram_11062011-2.jpg?itok=iZY9HosI)