Regional Conditions for Cooke City Area

From email: "I saw some older slab avalanches on The Thunderer mountain, in northeast YNP (observed today). These avalanches happened on westerly aspects around 9700'. I'd hypothesize that they happened in correlation with the very strong westerly winds that happened around Feb. 21-22." Photo: B Fredlund

From email: "I saw some older slab avalanches on The Thunderer mountain, in northeast YNP (observed today). These avalanches happened on westerly aspects around 9700'. I'd hypothesize that they happened in correlation with the very strong westerly winds that happened around Feb. 21-22." Photo: B Fredlund

This avalanche likely release naturally Sunday night (2/28). Photo: C. Tuholske

This avalanche was triggered by a snowmobiler on Saturday (2/27). Photo: C. Tuholske

Skiers saw this slide in Hayden Creek on 2/25/21. It appeared up to 4-6' deep and 200' wide. ENE aspect at 9,800' elev. Photo from IG: @vt.to.mt

Skiers saw this slide in Hayden Creek on 2/25/21. Photo from IG: @vt.to.mt

Skiers saw this slide in Hayden Creek on 2/25/21. Photo from IG: @vt.to.mt

Avalanches seen on windloaded slopes in Hayden Creek. Likely broke 2/21 or 2/22.

Photo: M. Simone

This natural avalanche on the SE shoulder of Mt Abundance avalanches regularly from wind-loading. Photo: S. Strenge

This avalanche on the east face of Wolverine Peak outside Cooke City was triggered by a cornice on 24 February. Although it did not propagate wide, it ran far. Photo: S. Strenge

A natural wind slab avalanche beneath a cornice on Henderson Mountain, near Cooke City. It appears to have broken at the new-old interface, 2-3 ft deep and ~300 ft wide. Likely ran overnight on Monday 2/22/21 or early morning Tuesday 2/23/21. 

Photo: GNFAC

A skier saw this natural avalanche at 9,000' on the east side of Republic Mountain on Tuesday, 2/23. Photo: J. Dobronyi

Snowmobile triggered slide on Crown Butte, outside Cooke City. 2/18/2021

Snowmobile triggered slide on Crown Butte, outside Cooke City. 2/18/2021

Wind-slab avalanche on the shoulder of Fisher Mtn. at about 10,000' elevation. This is the likely type of avalanche and type of location for slides in Cooke City right now. Photo: GNFAC

From FB: "Saw recent wind slab natural on NW facing start zone of tube south of Titanic. Ran into titanic approximately 500' vertical where tubes join. D2 in size. No other signs of instabilities noted." Photo: B. Zavora

A group of riders noticed this avalanche on the NE side of Scotch Bonnet on Saturday, 2/13. It likely occurred the day before. Photo: K. Yates

This avalanche on the northeast side of Scotch Bonnet observed on 2/13. The slide likely occurred on Feb 11 or 12. Photo: R. DeSilva

From obs: "Large avalanche from Feb 3-7 cycle in Pidex Bowl. Large avalanche from the same cycle that ran full track in the main Rip Curl gully. Wind slab released on the steep slope above, 15' tall trees are pushed over, and it ran all the way to the bottom of the run." Photo: N. Hance

This avalanche was snowmobile triggered on Saturday, 2/13/2021, near Daisy Pass. Its a steep, SE facing slope. Photo: GNFAC

This small avalanche was snowmobile triggered on Saturday, 2/13/2021, near Daisy Pass. Its a steep, SE facing slope. Photo: GNFAC

This large natural avalanche crown was observed 2/13/21 and likely broke between 2/9 and 2/11 when the area received 3-4 feet of heavy snow followed by strong wind. Photo: Z. Peterson

From email on 2/11: "interesting Av. activity in a Central Park - mid-lower Woody. This is an area that cross-loads like crazy, so it's not surprising to see slides, but the extent was impressive; essentially, slides propagated across the entire zone. These are all mid-slope ~9,000-9,200'"

Photo: J. Logan

From email on 2/11: "interesting Av. activity in a Central Park - mid-lower Woody. This is an area that cross-loads like crazy, so it's not surprising to see slides, but the extent was impressive; essentially, slides propagated across the entire zone. These are all mid-slope ~9,000-9,200'"

Photo: J. Logan

This natural avalanche occurred on a wind loaded, NE aspect above Henderson Bench outside Cooke City on (likely Feb 8 or 9). Wind-loading has been the main avalanche concern. Photo: Z. Peterson

This large avalanche on the SE face of Mt Abundance, north of Cooke City, released naturally in the last 48 hours. In the photo you can see the fingers of windblown snow from strong westerly wind. Photo: S. Strenge

The main gully on town hill went naturally last night (2/9) with a 3-4' crown. Photo: B. Zavora

A natural storm slab avalanche on a wind-loaded slope west of Cooke City. Photo: B Fredlund

A natural storm slab avalanche on a wind-loaded slope west of Cooke City. Photo: B Fredlund

From email: "Many, many collapses, with one that was about an acre in size, with cracks 30 yards away, and several house size. Loudest was after we had turned around, and 2nd skier started down - a very loud sharp crack, followed by rumbling. But low enough angle that nothing went." Photo: T Parrie

Riders east of Cooke City noted a couple of recent avalanches of Hwy 212 east of Cooke City and just west of the state line. Photo: N Gaddy

From obs: "Skiers traveling on South facing slope at 9,100ft elevation ascending Miller Trees remote triggered from skin track (second lap) a wind slab on a steeper East facing slope that slid to gully floor and out to Sheep Creek. Westerly wind was blowing with gusts carrying snow to load the east-facing side of the gully. Crown was approximately 4ft at the crest of the gully’s slope. Cracking visible in the photo from skin track traveled up to crown 50yrds away. Pit dug at similar elevation on South facing slope yielded slight cracking within the storm slab but no propagation (ECT16N)." Photo: Anonymous

Photo: B. Fredlund

Photo: B. Fredlund

A 100’ wide by 12”-24” deep avalanche was triggered by a skier on a North East aspect of Woody Ridge at 9000’. Skier was carried and partially buried after arresting on a tree. Photo: Anon

A large avalanche failed naturally on January 30th. It broke deep in the snowpack on a layer of weak facets. Photo:L B. Fredlund

Skiers northwest of Cooke City observed many new slab avalanches on all aspects from mid to upper elevations. Some stepped down onto older persistent weak layers. Photo: B. Fredlund

Skiers northwest of Cooke City observed many new slab avalanches on all aspects from mid to upper elevations. Some stepped down onto older persistent weak layers. Photo: B. Fredlund

Skiers northwest of Cooke City observed many new slab avalanches on all aspects from mid to upper elevations. Some like this one stepped down onto older persistent weak layers. Photo: B. Fredlund

A large avalanche failed naturally on January 30th. It broke deep in the snowpack on a layer of weak facets. Photo: T Parrie