24-25

Small slide in terrain trap. Looks to be old, likely from before the wind event that occurred mid last week. A snowmobile track leads into it with wind-drifted snow covering the track.

Toured up into the Blackmore area today and found a pretty interesting upper snowpack with everything below roughly 8500’ wet from yesterday’s green housing and up slope winds in the Hyalite area. From trailhead to our peak elevation at 9500’ the new snow from last night ranged from a dusting to about 3 inches and capped the wet snow. Above 9000’ winds were actively loading the snow and I got cracking and a very small slab to release on a small wind drifted roll over at 9500’ on a N aspect. Later in our tour we dropped a cornice on an E slope and there was no avalanche activity, albeit the snowpack below the cornice seemed to be very thin as the cornice pulled off most of the surface snow and exposed a lot of rock. Overall decent ski conditions above 8500’. 

We experienced several collapses and had propagation in multiple ECTs performed.  HS varies between 85-105cm. Photo from 9940

Photo: BMG

Photo: BMG

Today, we toured up and out of the north boundary of Bridger Bowl: up the Ramp, into Wolverine Bowl and on top of Texas Meadows. We got eyes on a lot of terrain north of Bridger and were able to dig in six or more different locations, with up to 12 extended column tests. Generally, we found a similar snowpack here as we have seen in the rest of the Bridger range: a slab of varying depths but generally about a foot thick on top of 1-2 mm facets generally in the middle of the snowpack.

In our pits near the top of the ridge, we got unstable test results with propagation on top of the facets. But as we dropped elevation, we found that we were unable to replicate propagation, and only got ECTN scores. These pits at lower elvations looked very similar to what Ian and I found just north of this area on Thursday (Ob from the Throne). One notable pit finding was a very thin layer of surface hoar near the top of the Ramp, as noted in our snowpilot (attached). 

Pit propagation was our first sign of instability, and as we continued along ridge past Wolverine we came across a R2 D2 slide in the Hourglass chute above Wolverine. It looked to be triggered by an intentional cornice drop, was around 12 inches deep at the crown, 100' wide and ran 850' vertical feet. It looked around three days old. As we skied down into Wolverine from the Ramp, we noted two other avalanches that seemed like they broke during the loading event that occurred last Sunday/Monday (12/15-16). These slides looked similar to the natural avalanche noted on Saddle this Thursday (Saddle Peak avalanche observation). 

Throughout our tour, our snowpack layers looked very similar. Pit propagation up high and recent avalanche activity showed us that the odds of triggering an avalanche in steep, wind loaded terrain were higher than we were comfortable with riding today. At lower elevations, our findings indicated the odds of triggering an avalanche are becoming less likely.