Trip Planning for Northern Gallatin

Natural avalanche that occurred at Bridger early on 5/9/22. There were many similar depth natural crowns along the ridge that broke within the recent snow that fell over the weekend.

Crown of a natural avalanche that occurred at Bridger on 5/9/22. There were many similar depth natural crowns along the ridge that broke within the recent snow that fell over the weekend.

Obs 5/9/22: "found an intact graupel layer buried by 10-14” of fresh snow. Got cracking on it (ectn 17, ct 18) but no propagation. Also saw lots old of storm slabs/wind slab crowns."

Natural wet loose avalanche in Beehive Basin. Occurred on Wednesday 5/4 after new snow fell on Tuesday.

Wet loose snow avalanches of recent 6" of snow. They likely occurred when the sun came out Wednesday morning, or at the end of the storm on Tuesday. GNFAC

"5/3/22 at approximately 4:00pm a storm slab avalanche occurred in beehive basin on a west aspect @9000 ft. This slab was 6-8” deep and propagated around 50’. No one was buried, however we aren’t sure if anyone was caught because we were not the party who triggered this avalanche. We did witness the party drop in but quick went out of sight." Photo: H. Bigos-Lowe

From obs 5/1/22: "This morning we toured south of Flathead Pass to check out the conditions. We noticed on our way up that the freezing line was ~7500 ft. The punchy and wet surface crust became quite supportive and icy at this altitude. We dug a pit at ~7900ft on a NE aspect. At this location, the overnight snow totaled only 2cm but we observed more significant wind deposition in and around the trees of about 10cm. Our shovel shear tests resulted in an easy shear at 120cm and hard shear (Q1) at 90cm. We saw no results from the ECT but, upon shearing the ECT block, we were able to pop off the block at 90cm with a surprising amount of energy (see photo). This block was quite consolidated, so much so that it remained intact as we pushed it out of the pit. With this observation, we stayed off steeper terrain today and will be looking for increased instability at this interface as temperatures warm." Photo: E. Shreier

From 4/30/22: "...there were several wet loose avalanches at Bridger today. Some with ~5cm of snow on top, maybe from yesterday or earlier in the week, and some new this morning. We watched a relatively slow moving natural size 2 come down Colter's area around 10:30. We also ski cut a size 1.5 from the skiers right of the Lower Nose (NE asp) around 9:45 which ran on the melt freeze crust from earlier this week. It moved slowly but I was surprised by how much mass it entrained. A couple other ski cuts just above had produced smaller size 1s. The debris stopped on top of an older debris pile which was significantly larger and had run significantly further. (You can kind of see the difference in the photo). There was also widespread roller balling and pinwheeling on all aspects and elevations. Note - sizes are D sizes..." Photo: N. de Leeuw

Skiers reported shooting cracks from their skis while ascending the terrain at Bridger Bowl. The group later remotely triggered an avalanche from 100'+ away that ran through the "Pearly Gates" and "Patrol Chute". 

On 4/18/22 near Cooke City we witnessed natural rollerballs and pinwheels by 11 am, and a couple wet loose slides below cliffs on southerly slopes around noon, and were able to easily trigger pinwheels on west-southwest aspects around 1230-1pm. Photo: GNFAC

A large drift on the Ramp just north of Bridger Bowl. Photo: GNFAC

Drifts cracked and slid on steep rollovers north of Bridger Bowl. Photo: K Hammonds

An avalanche on Wilson Peak that caught two skiers and injured one on 4/3/22. Photo: GNFAC

We pulled the Flanders weather station in Hyalite Canyon. The road will close to vehicles from April 1 to May 15. Photo: GNFAC

This natural wet, loose avalanche on the east face of Baldy Mtn in the Bridger Range likely released on March 27. Photo: B. Finch

This natural wet, loose avalanche on the east face of Baldy Mtn in the Bridger Range likely released on March 27. Photo: B. Finch

On 3/27/22 Big Sky ski patrol witnessed many natural wet slides in closed terrain. Photo: BSSP

"We also conducted avalanche mitigation on our Cabin’s Road at 4:30pm. The snowpack in this zone doesn’t get skied and is representative of the backcountry. The slope is ENE around 8,400’. Several wet slab avalanches were produced with explosives and ski cutting. The avalanches ranged from R4/D2 to R2/D1. They all hit the road and several crossed, and buried, the Cabin’s Road. Although most of this mitigation was done with explosives, it took minimal effort with skis to get snow moving. The crowns were 2-3’ deep and ran on the ground." Photo: YCSP

On 3/27/22 Bridger Bowl ski patrol witnessed many natural wet slides in closed terrain, and in adjacent backcountry terrain. Photo: BBSP

On 3/27/22 Bridger Bowl ski patrol witnessed many natural wet slides in closed terrain, and in adjacent backcountry terrain. Photo: BBSP

Natural wet slab avalanche on Cedar Mtn. Observed 3/26/22. Photo: J. Gerardi

Natural slab avalanche on the Sphinx. Observed 3/26/22. Photo: J. Gerardi

This avalanche occurred after a skier descended the slope on March 26. East-facing at 10,000 feet. Photo: E. Young

On March 26 many natural wet slides occurred in closed terrain at Bridger Bowl. Photo: BBSP

From obs: "Southerly aspects had significant sluffing on the crust interface" Photo: M. Zia 

From obs: "Observed a D1.5 natural on the N side of Maid of the Mist, photo attached. Looked like the upper pocket slid, then triggered the lower slope. ~75m crown line on the lower slope, depth looked like between 20-40cm. Upper pocket, hard to tell with limited viz." Photo credit: M. Zia

The Big Sky Ski Patrol saw this natural avalanche on Cedar Mountain as it occurred. Photo: N. Laskowski

Multiple skier triggered avalanches observed on 3/14/22. Photo: Anonymous

Triggered from a ski cut on 3/14/22. Photo: T. Rider

Skiers on the East face of Mt. Blackmore triggered this slab avalanche while ski cutting the slope. The avalanche broke 50' below the skier. Photo: T. Rider

From email 3/12/22: "Hi there, just wanted to send you guys a neat pic of the climb, Code Red in Flanders from today 3/12. There was ice debris several hundred meters downslope from the pillar, which broke off at some point..." Photo: C. Robinson

From obs 3/12/22: "Upon descending a ~35 degree slope, I (the snowboarder) kicked loose a wind slab that propagated 100 feet wide, 8 inch deep (max, 4 inches at edges) wind slab that traveled approximately 300 feet (entire slope over 30 degrees) before settling in 2 debris fields, each about 30’ wide and with a maximum of 2’ depth. No one was swept by the debris/buried/injured."

From obs 3/12/22: "Upon descending a ~35 degree slope, I (the snowboarder) kicked loose a wind slab that propagated 100 feet wide, 8 inch deep (max, 4 inches at edges) wind slab that traveled approximately 300 feet (entire slope over 30 degrees) before settling in 2 debris fields, each about 30’ wide and with a maximum of 2’ depth. No one was swept by the debris/buried/injured."

From obs 3/12/22: "Upon descending a ~35 degree slope, I (the snowboarder) kicked loose a wind slab that propagated 100 feet wide, 8 inch deep (max, 4 inches at edges) wind slab that traveled approximately 300 feet (entire slope over 30 degrees) before settling in 2 debris fields, each about 30’ wide and with a maximum of 2’ depth. No one was swept by the debris/buried/injured."

Small, long running skier triggered wind slab avalanche on Mt. Blackmore in Hyalite Canyon (3/10/22). Photo: M. Carey

From obs (3/10/22) : "Today we triggered a small pocket of wind loaded snow while ascending (bootpacking) the East ridge of Blackmore. The convexity broke about 1 foot down and propagated about 10 feet wide. It ran the entire distance of the East face ~800’."

Photo: C. Firer

The yellow circle shows the skier triggered soft slab avalanche that was seen on the approach to Mt Blackmore. Photo: N. Roe

As we moved along a steep break over near Lick Creek, we triggered shooting cracks and an avalanche on a small test slope. The avalanche slide on a hard melt-freeze crust formed last week. Photo: GNFAC

As we moved along a steep break over near Lick Creek, we triggered shooting cracks and an avalanche on a small test slope. The avalanche slide on a hard melt-freeze crust formed last week. Photo: GNFAC