Lionhead Range

Two natural avalanches that likely happened in the last 24-48 hours. 500' wide. "Crown line extends basically the entire ridge in the background." Photo. H. Darby

The crown of a natural avalanche likely happened in the last 12 hours. This avalanche broke 200' wide, 3-4' deep, and ran "almost full path" to the trees below. Photo: H. Darby

Toured up an east facing slope near the northwest arm of Hebgen Lake. We did not experience any collapsing or cracking on or off our ascent route but we did experience whumpfs on the ski down. At the top of the ridge at 9000 ft on either side of our skin track were three different avalanches. They all looked to be natural. One was pre recent storms, one was perhaps 24-48 hours old and maybe 500 feet wide, and one looked to be very recent, perhaps in the last 12 hours. We got a good look at the recent slide. It had no tracks in or out of it. It was at least 200 feet wide and broke 1-1.5 meters deep, gouging to the ground in spots and ran to the trees almost full path. Besides the avalanches, near the ridge line was a 30° planar slope that had a small concavity. There were shooting cracks everywhere, and it looked like the cracks propagated into a slab that would have broken up more if the slope had been steeper. It almost looked like a crevasse field with how many cracks there were. Photo is included but I don't think shows just how broken up that "relatively benign" terrain was. I have never seen anything like that before! 

From facebook: "We saw 4 different avalanches today at the west end of lions head. One triggered close to us. We were at the bottom in a safe spot on a high spot. North 44.73482. West 111.36946. 100 feet wide 100 feet vertical. Broke to the ground. Afterwards we watched 4 more go from a 1/4 mile to 1/2 mile away from us as we were in a safe position on a high spot watching them go. I'm sure we triggered the first one from the bottom, but we were 100 feet from the slope toe."