Photos

On the way back to Lionhead.  Came upon this recent avalanche.  Rushed up to the group of 4 guys.  They were fine, not the guys who set it off.  The group of 6 we passed going there set it off.  The group of 4 said they saw these guys ... all on the hill at same time, stuck and climbing around the stuck guy.  All were okay but I hear one guy was shaken up. 4-5ft deep at break by 200-300ft wide, ran 400+ft. Photo: T. Anafarta

On 12/31 we saw an avalanche that appeared very recent, and likely triggered by a snowmobiler. It was on a west facing slope at 10,000', and was a hard slab 1-4 feet deep and 100' wide, ran about 200' vertical. AMu-HS-R3-D2-O. This was a clear sign that weak layers exist, especially where the snowpack is relatively shallower, and recent snow has been drifted into thick slabs that are unstable over this weak snow. Photo: GNFAC

On 12/31 we saw an avalanche that appeared very recent, and likely triggered by a snowmobiler. It was on a west facing slope at 10,000', and was a hard slab 1-4 feet deep and 100' wide, ran about 200' vertical. AMu-HS-R3-D2-O. This was a clear sign that weak layers exist, especially where the snowpack is relatively shallower, and recent snow has been drifted into thick slabs that are unstable over this weak snow. Photo: GNFAC

On December 31, 2022 a snowmobiler was killed in a very large avalanche north of Cooke City, MT. The avalanche occurred near Daisy Pass on Crown Butte on a southeast facing slope at 9,800’. The avalanche appeared to be 2-4' deep, 500' wide, 600' vertical, and broke on weak snow near the bottom of the snowpack. Photo: GNFAC

On December 31, 2022 a snowmobiler was killed in a very large avalanche north of Cooke City, MT. The avalanche occurred near Daisy Pass on Crown Butte on a southeast facing slope at 9,800’. The avalanche appeared to be 2-4' deep, 500' wide, 600' vertical, and broke on weak snow near the bottom of the snowpack. Photo: GNFAC

On December 31, 2022 a snowmobiler was killed in a very large avalanche north of Cooke City, MT. The avalanche occurred near Daisy Pass on Crown Butte on a southeast facing slope at 9,800’. The avalanche appeared to be 2-4' deep, 500' wide, 600' vertical, and broke on weak snow near the bottom of the snowpack. Photo: GNFAC

Snow above collapsed into the trench from my sled, looked to have broken on a weak layer about 1.5’ down. 

From email: Dug a pit on a NW aspect near the bottom of Lick Creek. Saw sugary facets 50 cm down from the surface of the snow. Perfromed an ECT and got ECTX. 

Toured up to the east face of Mt. Blackmore today. We observed two small natural loose dry avalanches occurring right around noon on the new/old snow interface at about 9700' on the E aspect. The largest one ran about 200 feet down into the bowl. 

We observed a hollow snowpack on our ascent and dug a pit at 9600' just below the northeast ridge. We found several weak layers that were fracturing beneath two well-defined crusts. We got a CT2 @ 135cm, CT11 @ 130cm, CT13 @ 118cm, and CT15 @ 115cm; in our extended column test we got ECTP15 Q2 @ 130cm.

Big Sky Ski patrol triggered this very large deep slab avalanche with explosives during routine mitigation work on 12/28/22. Photo: BSSP

On 12/28/2022 from the lower south boundary of Bridger Bowl, ski patrol saw an old avalanche crown and debris on steep rolling terrain below the large cliffs on Saddle Peak. Appeared to be 1-2 days old, 2 feet deep and 60 feet wide, N-R2-D2-O

Natural avalanche in Sage Basin. Appear to have broken on a layer of facets underneath the new snow. Photo taken 12/28/22. Likely occurred early morning or overnight. Photo: GNFAC

Natural avalanche in Sage Basin. Appear to have broken on a layer of facets underneath the new snow. Photo taken 12/28/22. Likely occurred early morning or overnight. Photo: GNFAC

36” total. 24” sugar on bottom. 

From Email: It was actually great riding up there. Just no base once you broke through. Definitely solid on top and held weight of the sled. 

Snowpack at 8000 ft in pioneers is about 2 feet deep and mostly facets. About a foot of 3 mm large squares on the ground, a slightly more dense 4F- layer of crust and facets and another foot on top of that of soft NSF and new snow. Intentionally triggered a very small test slope, slab failed on the lower facet layer. See pics of quick pit and test slope results. Boot and ski penetration to the ground. Weak.

Snowpack at 8000 ft in pioneers is about 2 feet deep and mostly facets. About a foot of 3 mm large squares on the ground, a slightly more dense 4F- layer of crust and facets and another foot on top of that of soft NSF and new snow. Intentionally triggered a very small test slope, slab failed on the lower facet layer. See pics of quick pit and test slope results. Boot and ski penetration to the ground. Weak.

Large avalanche in the 2nd Yellow Mule that is probably 2-3 days old, and likely broke on the weak layer near the bottom of the snowpack. Photo: GNFAC

A large avalanche in the 2nd Yellow Mule that was probably 2-3 days old, and likely broke on the weak layer near the bottom of the snowpack. Photo: GNFAC

We saw two large avalanches in the 2nd Yellow Mule that were probably 2-3 days old, and likely broke on the weak layer near the bottom of the snowpack. Hard slabs on heavily wind-loaded slopes. Photo: GNFAC

We dug in the second yellow mule, NE aspect 9,300' and HS was 93 cm. Here we had ECTP26 on the layer of facets near the bottom of the snowpack.

We saw two large avalanches in the 2nd Yellow Mule that were probably 2-3 days old, and likely broke on the weak layer near the bottom of the snowpack. Hard slabs on heavily wind-loaded slopes. Photo: GNFAC