We (a group of four riders) rode down the narrow canyon between Beer and Whiskey Hill. After getting through, we looked up at Whiskey and saw that the entire hill had broken loose down to the boulders. We then saw a snowmobile laying on the ground, partially wedged into the wall left by the big slab that came down. Two men were on top waving their hands yelling for help. We immediately believed someone was buried and prepared to assist with rescue with our beacons, probes, and shovels. The men on top then yelled down that no one was buried. Evidently two riders started to climb Whiskey. The leading rider triggered the slab just has he reached the top. He rode off of the last slab and slammed into the wall left behind (crown face) bending his handlebars to the windshield. His buddy below was able to turn out and outrun the slide, which was amazing because of the thick trees at the base of Whiskey. They were both very lucky. We were glad to not have to be involved in a rescue. Turns out the two riders just wanted help pulling the sled just below the slab wall over the top. With 8 riders and a lot of rope, we hoisted the sled over the top.
I can't believe the two attempted to climb Whiskey that day with the avalanche danger rate High on your site. More questionable was the fact that both were climbing together. Had they both been buried, we would have observed the slide and moved on, with no knowledge of the slide being human triggered. The state should require avalanche safety courses as part of the snowmobile registration process.
Slight edit by forecaster - Lees