Southern Gallatin

On December 27, two snowmobilers were caught and killed in an avalanche on Scotch Bonnet Mountain, north of Cooke City. A group of 8 snowmobilers from Minnesota were on their second day of riding when 2 of their machines got stuck on the SE face of Scotch Bonnet Mountain. Two members of their group rode up to help them dig out and the avalanche was triggered soon after. It broke 4-5 feet deep, ran 300 feet wide and 500 feet vertical and killed 2 riders, burying them under 4-5 feet of debris. Everyone had rescue equipment and they were recovered by their party. Park County Sheriff Search and Rescue brought the victims to town. The avalanche broke on a layer of facets 1.5 feet off the ground underneath a thick slab of wind drifted snow. The avalanche is classified SS-AMu-R2-D2.5-O.

From email: "My partner and I went out to Ernie Miller today via the standard bacon rind uptrack. On the traverse across the moderate terrain, we experienced many whumpfs, some large enough to knock snow out of trees. We went up to about 9100ft on ole Ernest and dug a pit, performed an ect, and got  propagation all the way across a layer maybe 4-6 inches above the ground at 25 whacks. On the same whack (the 25th), a layer about 12 inches above ground also collapsed and propagated across."

There were many natural avalanches that were breaking on facets near the ground (4-6mm). The 3 feet of snow that fell created unstable conditions and avalanched during the HIGH danger. Most slides were less than 100 feet wide. By GNFAC.

ECTP 8 @ 15cm 7800' E. on Specimen Ridge. LOC: Fist hard basal faces below a decomposing crust about 10cm off the ground Lots of whomping on lee and sheltered slopes. We noticed a few pinwheels at later in day below 7500'. Generally poor structure and poor strength. I don't know what SWAG notation for sagebrush is but lots of that...