Snow Observations List

NW aspect 8900’ 

HS 175cm

ECTP11 @120cm on 4F facets

This test result changed our intended plans and we decided to stay off steep slopes. We experienced intermittent light snow and light wind all day. 

We rode to Ski Hill and dug. HS was 230cm and the top 60 cm was from last week. the top 25 cm was F hardness powder. No wind when we were there. We got an  ECTX. We then rode to the old weather station at 8700' and had HS 210 cm. Same layering but got ECTP20 about 65 cm down at the interface of the old snow surface and this weeks deposit. I looked with a hand lens and did not find facets, just a density change. But with the top foot being F powder it would not take much to build drifts that would slide. 

We also saw one small slide on the drive on a roadcut a Fawn Pass that looked to be 1.5' deep and 50' wide, soft slab. 

Pretty mild observations:  north ridge above Hebgen, some woomfing on the ridge pretty subtle.  This was yesterday morning, on the ridge top.  Tons of new snow.  Also point release in the slide area, north face of slide scare, above quake lake, visible from the road new in the last couple of days.  Obviously natural trigger there.  

I had heard a rumor from snowmobilers that there was a human-triggered avalanche on Lionhead on Thursday the 23^rd.  While in Taylor Fork yesterday, we ran into one of the individuals that was a part of the incident. The jist of it was he and a buddy were climbing together, and he uncovered a rock that his buddy then hit.  While the first rider continued to climb, he triggered a slide, and it partially buried the second rider.  He was able to deploy his airbag but was carried approximately 100 yds down the slope where he was buried.  Other members of his group quickly found him. 

I think this natural avalanche happened about 24-48 hours ago.  (pretty sure it wasn't there 2-3 days ago?). It's an E, SE aspect, about 9200', between Cooke City and Silver Gate.

A group watched a natural avalanche from the Pilot Creek Parking area cascade down the mountainside on Friday, 2/24/23 at 5:00 PM. 

From IG. “I spotted a large crown this morning on the E face of Bole. The crown appeared to be pretty deep, at least a few feet, and propagated quite wide. It also looked like there was a debris path coming down the apron of the E face of Hyalite peak, but I was too far away to know for sure.”

We rode to Henderson Bench and dug a pit on a northeast aspect at 9,400'. We had ECTX x2. Last week's snow had settled to about 2.5' and was well bonded. There was one harder wind blown layer in the middle that created an upside down density change, but it did not react in stability test. Total depth was 266cm. We measured 0.65" SWE in the top 10" of snow which we assume is what fell since yesterday morning.

We rode over to Scotch Bonnet and dug on a SW aspect at 9,700'. We had some ECTNs near the middle of the last week's snow, and 2x ECTP29 on facets down 3.5'. We did not see any obvious stability concerns in our pits, but the large amount of snow and wind last week followed by many avalanches is enough to keep danger elevated for a couple more days, especially with continued snowfall and/or wind-loading.

We rode on Buck Ridge today to do some maintenance on our RAWS station for the fire folks and check on the yellow mule cabin.  Where the wind hadn't blown it away yet, there was 4" of snow from over night on top of very firm snow, likely from the last round of wind.  The most sheltered areas behind trees and down in the basins still had some deeper, soft snow and better riding.  We saw one small wind slab avalanche in the new snow above Beaver Creek on a north aspect. 

I toured up to hyalite lake today to check out how the west facing walls in the main fork of hyalite  (hyalite lake drainage ) were stabilizing after last weeks wind.  On Friday I noticed “Provo’s run” (large path near overlook mtn) slid from the top which appeared to have slid due to the heavy wind loading.  The slid looked to be about 24” deep and ran full path .  So today I checked out the west facing walls close the hyalite lake and around 9500’ the upper sections of these slid paths were wind effected and unstable, and I did not ride them 

I dug a pit around 9500’ on the west facing wall near the lake and got unstable results.  ECTP 11 which propagated below the recent wind load from last week.

the snow pack is 240 cm deep and is nice and consolidated without  any major layers on several of the pits I dug at several elevations on these upper elevation west facing walls accept for the wind load on the upper elevations pits 

We triggered and were caught in an avalanche very near town.  We skied the east side of Miller,  dropped down to descend the very eastern slope just above town. While standing on approximately a 30-35 degree slope we experienced a release immediately above us.  The crown line was approximately 18-24" and extended appx 50' across. We were caught for about 150' before coming to a stop and buried to the thigh. The entire slide was appx 400' from top to bottom.  It was appx a D2.

Today we toured to a ridge across from the west face of Republic Mountain. We observed multiple natural avalanches on several aspects. Winds were calm until around noon, and then picked up in the afternoon and were heavily loading north aspects at this location. 

From email 2/26/23: "I just talked with a fella that reported his buddy was buried up to his chest in an avalanche yesterday off of east abundance, near the cliffs. He reported a 4' crown and 200' wide. His buddy was snowmobiling."

Triggered wind slab in southern Gallatins

Experienced whumpfs, cracking, and remotely triggered collapses on E aspects at 9000’ near ridgelines. The wind slabs were very reactive but thin, ranging from 2” to 5” deep. 

From IG message 2/25/23: "Hey just wanted to report a Cooke city avalanche from today. Happened at 3pm caused by a skier coming down a south facing slope above Round Lake. Everyone was fine, he lost his skis and everyone learned"

From email 2/25/23: "... a good sized slab avalanche on Fan, NE Face. Crown height hard to estimate but looked like a 2’ or so. Maybe running on interface from when it got cold earlier in the week? Possibly deeper than that but sure could have loaded that much this week. Anyway- very white bed surface, good propagation, 200’ -300’ crown length, debris stopped on upper bench. D2.5. Likely triggered by cornice fall."

This natural avalanche was seen today on E. Henderson Bench.