This is 3rd party information. A snowmobile climbed out of a canyon to reach the top. The angle went from 15-20 degrees on the first 2/3 of the mtn. Then decreased to about 10 degrees. The snowmobile approached the bottom of the 12’ tall cornice having to turnout from getting to the top when the cornice failed. It was a slow moving slide but carried the snowmobile and rider approximately 100 yards from the point of failure. No burial. No damage. Reports of the cornice chunks were larger than a snowmobile. The slide had stopped just before the slope changed back to the steeper angle.