Regional Conditions for Cooke City Area

"A small slide approx 100 ft wide ran about 40 vertical feet. Crown was 3-4 feet deep. Aspect, SE. Trigger unknown however tracks indicate it was likely a snowmobile trigger." Photo: Reed Youngbar

Cooke City is getting deep! The total snow height is 315 cm. Our pit results on Scotch Bonnet were a variety of ECTNs in the upper layers of the snowpack. When placing our probe for stability tests we could feel the weak snow near the ground as our probes just dropped through the lower 60 cm of the snowpack. I am still worried about the deep layers, but it has been a while since they performed and it seems like it will take a big trigger (i.e. a cornice drop), a big storm to add weight, or some really bad luck to trigger one of the monster avalanches on the basal facets. Photo: GNFAC

We rode into Lionhead and found good stability. A sledder highmarked up the hill and then came down right next to us, confirming our results. Wind-loading from yesterday is still a concern, and so are the facets near the ground, although less so than a couple weeks ago. Photo: GNFAC

"I observed this collapse & propagation as I stepped over some wood in the skinner on the north ridge of Mount Ellis this morning, ~8000’, due East. I was tailing Chabot and his partner, and they had passed this way just minutes before." Photo: D. Rider

Natural avalanches on a west aspect at about 8300' a few miles west of Cooke City. These slides are about 2' deep and 30-50' wide. Photo: B Fredlund

"...a fresh avalanche observed out there today.  A south aspect around 9400', estimated to be 2-3' deep and 75' wide." Photo: B. Fredlund

"S facing slope, not sure how it was triggered, a foot deep crown at most." Photo: S. Strenge
 

"We’ve seen many instances of cracking and wind slab breaks the past two days riding in Cooke, most happened as we sledded past or down the slope." This slide is 4" deep. Photo: S. Strenge

"We’ve seen many instances of cracking and wind slab breaks the past two days riding in Cooke, most happened as we sledded past or down the slope." This slide is 4" deep. Photo: S. Strenge

On private property, this small child triggered a slide and climbed out of the debris, not buried. A very close call! On the heels of this large snowstorm there are possibilities of children getting caught on road cuts or any open hill!  Photo: Anonymous

We triggered this avalanche in the second Yellow Mule off Buck Ridge on 2/6/2020 It is on a small roll/cornice "in the flats". It broke within the current 2-3' storm snow. Photo: GNFAC

A snowmobiler triggered this avalanche in the second Yellow Mule off Buck Ridge on 2/6/2020 It is on a small roll/cornice "in the flats". It broke within the current 2-3' storm snow. Photo: GNFAC

We saw this natural crown that broke within the current 2-3' storm on a small terrain feature. It is in the second Yellow Mule off Buck Ridge on 2/6/2020. Photo: GNFAC

The Nose of Town Hill avalanched on Feb. 1 due to the strong SWerly winds and looked to be triggered by a cornice fall (estimated 2-3' crown, about 75-100' wide).  Photo: B Fredlund

SEerly aspect around 8600'.  A thinner, smaller storm slab, triggered by dry loose from above. Photo: B. Fredlund

SWerly aspect around 9500'.  Deep slab, mid-slope.  I'd estimate that crown to be about 4-6' deep. Photo: B. Fredlund

Winds Friday night transported snow creating fresh drifts that avalanched naturally over the weekend. This one on the east side of Woody Ridge appears to be 2-3' deep and 50' wide. Photo: GNFAC

From email (1/30/2020): "2 natural avalanches that ran last night, just west of Cooke City.  Both slides were on easterly aspects around 9500'."

From email (1/30/2020): "2 natural avalanches that ran last night, just west of Cooke City.  Both slides were on easterly aspects around 9500'."

We triggered this avalanche of wind-drifted snow as we approached very carefully from a low angle slope above, on 1/30/2020. This is near Lulu Pass outside Cooke City on a south facing slope at 10,000'. It broke within recently drifted snow, but these slabs could be enough weight to break deeper and wider on sugary layers deep in the snowpack. Photo: GNFAC

We triggered this avalanche of wind-drifted snow as we approached very carefully from a low angle slope above, on 1/30/2020. This is near Lulu Pass outside Cooke City on a south facing slope at 10,000'. It broke within recently drifted snow, but these slabs could be enough weight to break deeper and wider on sugary layers deep in the snowpack. Photo: GNFAC

We triggered this avalanche of wind-drifted snow as we approached very carefully from a low angle slope above, on 1/30/2020. This is near Lulu Pass outside Cooke City on a south facing slope at 10,000'. It broke within recently drifted snow, but these slabs could be enough weight to break deeper and wider on sugary layers deep in the snowpack. Photo: GNFAC

We triggered this avalanche of wind-drifted snow as we approached very carefully from a low angle slope above, on 1/30/2020. Triggered from where Alex is standing. Near Lulu Pass outside Cooke City on a south facing slope at 10,000'. It broke within recently drifted snow, but these slabs could be enough weight to break deeper and wider on sugary layers deep in the snowpack. Photo: L. Browning

We triggered an avalanche of wind-drifted snow as we approached very carefully from a low angle slope above, on 1/30/2020. It broke within recently drifted snow, but these slides could be enough weight to break deeper and wider on sugary layers deep in the snowpack. Photo: GNFAC

The 10' deep avalanche in 2nd Yellowmule is almost completely filled in now. In its place are massive cornices overhanging the slope. Give these beasts a lot of extra room as they can break back far from the edge. Photo: GNFAC

Ian Hoyer stands in a snowpit in Beehive Basin. Avalanches are getting harder to trigger, but in more shallow areas we are still finding a poor snowpack structure. The stability test scores are climbing higher, but still propagating and we did not ski the adjacent slope. Photo: GNFAC

February 1, King and Queen of the Ridge at Bridger Bowl (fundraiser). This is the Friends of the Avalanche Center’s second biggest fundraiser of the year. Come on out and help us raise money by hiking and skiing laps on the ridge. Prizes, camaraderie and a good time is guaranteed. Register with Bridger to hike in the event, and create a pledge page to raise funds with your Ridge laps.

From email:

"I wanted to make you aware of a snowmobile triggered slide in Lionhead today. Fortunately, I was not injured, was able to stay completely on top, climbed through the majority of the snow wash after seeing it begin to break, and relatively slowly slid down with the last of the moving snow while still on the machine. When I came to a stop, I stood up and was completely free of the snow. Our group is trained in avalanche safety, practiced beacon use prior to leaving town in the morning, were wearing avy gear, and were very fortunate that this ended up the way it did. 

A clear reminder that this can happen to any of us and to be careful out there."

Photo: Anonymous 

A large natural avalanche observed on the southwest face of Wolverine Peak. Photo: D. Wycoff

A large natural avalanche observed on the northwest face of Median Peak. Photo: D. Wycoff

Spotted the crown on our way down from Ripcurl yesterday, we got a closer look today when we toured into High Hayden. N aspect 10200' Photo: H. Coppolillo

Spotted the crown on our way down from Ripcurl yesterday, we got a closer look today when we toured into High Hayden. N aspect 10200' Photo: H. Coppolillo

This cornice triggered avalanche was on a NE facing slope at 9700'. It broke 300' wide, 3-6' deep and 150' vertical. It likely broke on 1/15 or 1/16/2020. Photo: GNFAC

The avalanche broke at the ground when it was triggered by a cornice fall. It broke 3-6' deep and 300' wide. Photo: GNFAC

This avalanche occurred on a heavily wind-loaded slope from a cornice fall. The area is to the north of Lulu Pass and Scotch Bonnet. Photo: GNFAC

Another view of the large natural avalanche on Mt Fox that occurred on 1/14/2020. Photo GNFAC

Another view of the large, hard slab avalanche that was snowmobiler triggered on 1/16/2020. Photo: GNFAC

"A south and southeast aspect of Mt. Wolverine around 9,500'-10,000'.  I'd estimate the lower crown to be about 3' deep.  And timing of the event maybe around Jan. 16.?" Photo: B. Fredlund

The crown of this snowmobiler triggered avalanche tapered to a thin slab. These thin areas of the slope are prime zones to trigger a slide from. Photo: GNFAC

This avalanche was triggered on 1/16/20. The crown was measured 15' deep and was knife hardness wind slab. The slide broke on a layer of faets that is found on many slopes in our forecast area. Photo: GNFAC