Toured into Beartrap Fork and rode South facing terrain off of Beartrap West between 9000 and 9700ft; beauty bluebird day with very light wind. There were already a good amount of lines on the face with a well established skinner. On our first run the snow was light and fluffy still and the sun hadnt done much to it yet. At the bottom when we were transitioning for a second lap, a party to the side of us stepped off their skis and postholed up to their thigh. This triggered a massive wumph in the meadow that everyone heard and felt, but there were no visible cracks to be observed. On our way back up, our friend Marvin was a good bit ahead of us and got another massive collapse around 9400 feet, again no cracking to be observed. He said he felt the whole slope settle beneath his feet. When we got up to the spot he triggered the collapse, we dug a pit on a 25 degree slope with a HS of 110 at 9460ft and 177 degrees South facing. The pit results were ECTP24 ~30cm from ground on 2mm basal facets on top of an old melt freeze crust. I suppose the sun was starting to slab up the snow, but it was rather surprising given the amount of tracks and it being triggered on a well established skinner.