Trip Planning for Northern Gallatin

From Obs. "Wind was swirling in Maid of the Mist yesterday, mostly upslope winds that were transporting snow, but inconsistently and were difficult to predict where they were loading. We did not find widespread wind loading, but did get a very small windslab to release just below the top of the ridge (max 3-4" thickness, see image)." Photo: C. Avis

We skied to the top of Mt. Ellis via the ridge from the north. There was light wind on the ridge, otherwise calm. Snowing steadily this morning and tapered off by noon-1pm with skies clearing after noon. There were 2-4" of low density new snow. We dug a pit off the ridgeline on a northeast facing slope at 7,800' and one pit at the top of the burned slope, east facing at 8,100'. Profiles attached.

The first pit had an ECTX and the second had propagation with extra force. There were 2mm facets 30cm off the ground in both pits which were slightly softer in the higher pit. Snow depth was 3-4 feet up high and around 2 feet lower in the thicker trees and along the trails.

Observed a fresh slide on the north side of Mt Blackmore, crown was already filling in, but looked to be a foot or two deep in steep rocky terrain to the skiers left of the north couloir. Photo: S Jonas

Lots of snow moving around in Hyalite this morning! Strong winds were moving snow at/above treeline, Lee aspects getting loaded. Photo S Jonas

Saw cracking of cornices on the ridgeline NE of Mount Blackmore. Just a little nudge released a significant portion. Photo: T Miller 

Snowpit from the top of Tyler's slope in Beehive Basin, W facing, 9200 ft. This is representative of an area with thin snow that is weaker

Probably already reported...but touchy storm slabs on Mt Blackmore. Attached is a photo of a natural from the approach, at the switchbacks to the upper basin.

Photo: Anonymous

Wind slab Blackmore south bowl - 10 Jan 2025

Wind slab along Blackmore trail. Good clue before we got above treeline where more wind was blowing and moving snow

We triggered this wind slab by triggering a smaller one above it while descending the NE ridge of Blackmore. 
~10-12" deep and 25' wide

Big wind slab on N face of Mt Blackmore. We watched it cut loose at 14:25 from cornice fall.

Good news is that it didn't trigger a deeper slide.

Snow on a post along the Blackmore trail shows how much snow has been falling. I suspect the slow and steady nature of snowfall is what allowed it to do this.

Storm slab avalanche that broke about 400 ft wide at 9200 ft in a ENE facing sub-cirque of Blackmore

Two storm slab avalanches on the east face of Blackmore 8-10 inches deep. One of them ran down the normal skin track.

image of snowpit from Mt Blackmore, NE facing, 9185', HS almost 5 ft

Skiers in the Main Fork of Hyalite Creek drainage spotted this crown below the upper cliffs on the Maid of the Mist. Photo: Anonymous

The one thing of note was a recent avalanche on the north face of Blackmore. Visibility was poor but it was a small pocket in a steep, rocky zone that broke near the ground. Photo: H Darby

Small cornice build up on lee aspects from north winds. Photo: H Darby 

There was recent avalanche on the north face of Blackmore. Visibility was poor but it was a small pocket in a steep, rocky zone that broke near the ground. Photo: H. Darby

Around 7 p.m. Monday night, a few miles up Portal Creek, triggered from bottom of slope.

Around 7 p.m. Monday night, a few miles up Portal Creek, triggered from bottom of slope.

Small wind slab in hyalite at the start to champaign slot, 7600’, WNW, ~8” crown. Photo: S Bonucci

Small wind slab in hyalite at the start to champaign slot, 7600’, WNW, ~8” crown. Photo: S Bonucci 

Divide Pk 9600ft SE facing snowpit on 27 Dec 2024 with ECTP27 and ECTP23 at 22" deep

Divide Pk 9560ft E facing snowpit, ECTP30 about 24" deep on 27 Dec 2024

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. Photo: E Heiman

There was some natural avalanche activity on the peak south of mt Bole. Photo: Anonymous

Observed from Flanders this morning. Presumed recent natural slide around ~9950 ft. on a E/NE aspect. Photo: E Webb

The power of the winds was emphasized by the scoured west side of the East Ridge of the Main Fork. Photo: E Webb

I dug a pit on the SE shoulder of divide at around 9600’ and got a ECTP 14 on the persistent weak created during the long dry spell layer buried from this weeks storms.  Photo: Anonymous

Plumes of drifting snow in the Bridger Range as strong winds blasted the mountains. Photo: GNFAC

From IG: On 12/15 "Storm slab broke about 200’ above us as skinning up the hallway coming from the north side on the throne." Photo: Anonymous

Photo: B Durrum 

Photo: M. Legler 

Gusty winds transporting snow in Taylor Fork on Saturday. Triggered a 4-5 inch deep wind slab that propagated about 50 ft at the top of a north east facing slope at 9,500 ft.

Photo: JP

Ice gullies snowpack

Photo: GNFAC

Snowpit on the Mt Blackmore 

Photo: GNFAC

Light winds below treeline had little to effect on the snow in the history rock meadows. It was clearly blowing up high, with exposed nw faces stripped of snow and active transport visible off of Blackmore. Photo: W Hubbard 

8" of new snow at the Grotto Falls TH. Photo: GNFAC