Avalanche Activity

Cooke City
Daisy Pass
Natural avalanche at Daisy Pass, Cooke City
Incident details include images
Daisy Pass
SS-N
Elevation: 10,000
Aspect: SW
Coordinates: 45.0497, -109.9640
Caught: 0 ; Buried: 0

Here are two photos of what I think is a natural slide from this morning (3/1). Looks like a natural slide across from Crown Butte at the top of Daisy Pass. Crown is at least a few feet. 

Forecaster note: The paths immediately to the left and right of this slope avalanched with a snowmobile trigger on 2/13. Photos and video are here: https://www.mtavalanche.com/node/24256


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Northern Madison
Buck Ridge
Third Yellow Mule / Skier triggered slide + sympathetic
Incident details include images
Buck Ridge
SS-ASu-R2-D1.5-O
Aspect: NE
Coordinates: 45.1912, -111.4430
Caught: 0 ; Buried: 0

Sled Skiing in Third Yellow mule... after an air onto the slope the impact from landing resulted in a fracture and failure to / near the ground... in addition, a remote trigger occurred on adjacent slope... 200-300 ft to the skiers right. No body was caught in either slide. Skier that initiated failure was moving at high speed and was beyond slide path before majority of snow movement began. 2 pits where dug prior to riding terrain. One on adjacent slope, we went through to ECT 30 and continued to hammer on the column through 40 wacks of double fist, full force before failure occurred 30 cm above ground. Second pit was dug on slope where slide was initiated... same results, very hard to get failure to occur. Snowpack depth varied from 125 - 180 cm in the area... our pits were dug in depths of around 125 cm and 170 cm respectively.


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Southern Madison
Cabin Creek
Snowbike triggered avalanche, Red Canyon near W. yellowstone
Incident details include images
Cabin Creek
HS-AMu-R4-D2-O
Coordinates: 44.8949, -111.2280
Caught: 0 ; Buried: 0

Riders triggered this slide on 2/28/21 near Red Canyon/Cabin Creek, north of West Yellowstone. Nobody caught or injured, but close call.


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Southern Madison
Taylor Fork
Sage Basin Avalanche
Incident details include images
Incident details contain video
Taylor Fork
SS-NC-R3-D2-O
Elevation: 9,250
Aspect: NE
Coordinates: 45.0607, -111.2720
Caught: 0 ; Buried: 0

This avalanche failed on a heavily wind-loaded slope in Sage Basin along the ridgeline. It may have initiated as a cornice fall or a wind-slab, but it broke down to deeply buried facets. Even though it was a small slope, the slide had enough power to knock down a tree and piled debris deeply at the bottom of the slope.


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Bridger Range
BRIDGER RANGE
Skier triggered cornice N of Peters Point, adjacent to Bridger Bowl boundary
BRIDGER RANGE
SS-ACu
Coordinates: 45.8512, -110.9480
Caught: 0 ; Buried: 0

From obs: "Observed a small avalanche while teaching a rec. 1 today for MSU. The light was too flat to see a crown. Based on the light wind, ski patrol obs. and our moving obs., I hypothesize that it was a dry, loose avalanche. L-N-R1-D1.5-I."

Patrol reported: "A midday report from [a skier] that he had released the Duane's Cornice (out of bounds to the north) as he travelled to the ramp had us looking for any tracks below, none were observed. It looked to step down and pull some older layers as it went through the lower pinch."


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Northern Madison
Buck Ridge
Natural avalanche on Buck Ridge
Incident details include images
Buck Ridge
SS-N-R3-D2
Coordinates: 45.1719, -111.3800
Caught: 0 ; Buried: 0

Natural avalanche on Buck Ridge. Observed 2/26/2021. Looks to have failed recently. Propagated widely.


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Northern Madison
Cedar Mtn.
Natural deep slab avalanches on Cedar Mtn
Incident details include images
Cedar Mtn.
HS-N-R2-D3
Elevation: 10,000
Aspect: E
Coordinates: 45.2268, -111.5120
Caught: 0 ; Buried: 0

These deep slab avalanches on the E face of Cedar Mountain (and lower flank) likely avalanched Feb 23 or 24.


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Northern Gallatin
Elephant Mountain
Elephant Mountain natural avalanche, Hyalite
Incident details include images
Elephant Mountain
HS-N
Aspect: E
Coordinates: 45.4382, -110.9900
Caught: 0 ; Buried: 0

Ice climbers across Hyalite Canyon near G2 saw a wide and deep crown across the east face of Elephant Mountain.


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Southern Madison
Beaver Creek
Small natural avalanche in Beaver Creek
Incident details include images
Beaver Creek
SS-N-R1-D1.5
Coordinates: 44.8720, -111.3610
Caught: 0 ; Buried: 0

This small natural avalanche broke on a steep, rocky slope in Beaver Creek.


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Cooke City
Hayden Creek
Deep avalanche on wind loaded slope near Cooke
Incident details include images
Hayden Creek
HS-N-R2-D2.5
Elevation: 9,800
Aspect: E
Coordinates: 44.9952, -109.9080
Caught: 0 ; Buried: 0

Skiers saw this slide in Hayden Creek on 2/25/21. It appeared up to 3-6' deep and 200' wide. ENE aspect at 9,800' elev.


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Cooke City
Wolverine Peak
Cornice triggered avalanche on Wolverine Peak
Incident details include images
Wolverine Peak
HS-NC-R2-D2
Elevation: 10,500
Aspect: E
Coordinates: 45.0530, -110.0100
Caught: 0 ; Buried: 0
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Cooke City
COOKE CITY
Natural Wind Slab avalanches around Cooke City
Incident details include images
COOKE CITY
SS-N-R2-D2-I
Aspect: NE
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

1. A natural wind slab avalanche broke 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. 

2. Another smaller wind slab also broke further down the path. 

3. A small slide under Sheep Mtn on a E aspect. Size 1, natural. Lots of transport today out north, with dense punchy snow on most aspects. Definitely slabbing up.

4. Photo attached. I saw this SS-N-R1D2 on an E aspect at 9,000’ on the east side of republic mountain into Republic creek. I’m guessing it involved the HN plus some wind loading on old facets on a steep rocky face.

5. Southeast ridge of Mt Abundance broke under the wind-loads. It propagated a few hundred feet.


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Northern Madison
Lone Lake Cirque
Natural and deep avalanche in Lone Lake Cirque
Incident details include images
Lone Lake Cirque
HS-R2-D2
Elevation: 9,000
Aspect: NE
Coordinates: 45.2771, -111.4640
Caught: 0 ; Buried: 0

The Angry Hairpiece in the Lone Lake Cirque broke as a deep slab sometime in the last 24 hours.


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Cooke City
COOKE CITY
Natural Avalanches, Thunderer Mountain
Incident details include images
COOKE CITY
SS-N-R2-D2
Elevation: 9,700
Aspect: W
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

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." 


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Northern Gallatin
Mt Blackmore
Natural on Ridge North of Blackmore
Incident details include images
Mt Blackmore
SS-N-R3-D2.5-O
Elevation: 9,100
Aspect: N
Coordinates: 45.4531, -110.9970
Caught: 0 ; Buried: 0

From Obs: "Driving back from Grotto Falls trailhead, from the east side of the reservoir I could see this slide on the ridge that extends north from Blackmore above Blackmore lake. The slide was on a north-facing slope around 9,100', large enough to see with the naked eye and clear as day with binoculars. The crown looked multiple feet deep and either meandered, partially hidden from view, by another ridge or a substantial second avalanche a hundred feet away."


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Southern Gallatin
Specimen Creek
Specimen Creek
Incident details include images
Specimen Creek
SS-N-R2-D1-O
Elevation: 8,200
Aspect: SE
Coordinates: 45.0265, -111.0480
Caught: 0 ; Buried: 0

From obs: "Observed 2 natural avalanches, both on the basal persistent layer I would guess. one maybe a week old, partially filled in (SS-N-D1R2-O), and one that ran in the last 24 hrs (SS-N-D1.5R2-O) on a SE aspect, 35 deg at 8200 ft. I thought it was interesting given the lack of new snow and seeming lack of strong winds in this area. 2/5 ECTs had propagation, we had two large collapses."


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Northern Madison
NORTHERN MADISON RANGE
Natural Avalanche, Northern Madison Range
Incident details include images
NORTHERN MADISON RANGE
SS-N-R2-D2-O
Coordinates: 45.2952, -111.4100
Caught: 0 ; Buried: 0

From email: "Observed natural deep slab probably happened overnight with the strong winds... snowpack in the area was about 3-5’ deep mostly 4F with 20+cm of F depth hoar at the bottom... obviously not strong enough to support the windload."


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Cooke City
Town Hill
Collapse on town hill near Cooke
Town Hill
Coordinates: 45.0256, -109.9370
Caught: 0 ; Buried: 0

"...but just as I was about to drop in a huge whumph and collapse occurred all around me so I bailed. Spooky. This spot has a shallow snowpack on what is essentially a shale field."


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Northern Madison
McAtee Basin
Snowmobile triggered Avalanches (2), McAtee Basin
Incident details include images
Incident details contain video
McAtee Basin
HS-AMu-R3-D2-O
Elevation: 9,600
Aspect: NE
Coordinates: 45.1769, -111.4520
Caught: 0 ; Buried: 0

From obs: "Triggered a large slide with a snowmobile. Went all the way to the ground. Crown seemed to range anywhere from maybe 3 ft to 10 ft. Large slabs of snow broke free and slid for about 100 yards."

A second sled-triggered slide occurred Saturday (2/20) on the ESE facing slope at the entrance to McAtee Basin. SS-AMu-R3-D2-O


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Northern Gallatin
Alex Lowe Peak
Natural Deep Slab on A. Lowe Peak
Incident details include images
Alex Lowe Peak
HS-N-R3-D2.5-O
Elevation: 9,500
Aspect: N
Coordinates: 45.4272, -111.0140
Caught: 0 ; Buried: 0

We saw this crown on 2/20/21. It likely broke 2/19 or 2/18.


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Northern Gallatin
Mt Ellis
Whumph on Little Mt. Ellis
Mt Ellis
Coordinates: 45.5777, -110.9550
Caught: 0 ; Buried: 0

From email:"At 6450 feet on a north facing aspect on Little Mt. Ellis I found a snow depth of 75 cm. I dug a pit and got a Ct -7. Ect - 18, both failing on ground facets at 15-20 cm depth. I didn’t see any slides, but I did feel and hear one whumpf on the way up."


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Northern Madison
Whumph and small avalanche in Gallatin Canyon
Incident details include images
SS-AW-R1-D1
Elevation: 7,500
Aspect: NE
Coordinates: 45.3186, -111.2560
Caught: 0 ; Buried: 0

"While on tour today above the canyon, we observed various snow surfaces. We found heavily windloaded slopes on E/NE aspects. Solar aspects began to develop rollers as rocks began to heat up around noon. We observed a small avalanche on E slope a drainage away, roughly 20 feet wide. While ascending a ridgeline at 7500 elevation, we had a massive woomph and crack that spread 100 feet from the ridge to a roller in the fall line."


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Northern Gallatin
Flanders Creek
Natural Deep Slab Flanders
Incident details include images
Flanders Creek
HS-N-R4-D3-O
Elevation: 9,600
Aspect: NE
Coordinates: 45.4330, -110.9430
Caught: 0 ; Buried: 0

From obs [2/20/21]: "We observed a large natural slide on Flanders Mountain that likely occurred on Thursday (2/18/21). The crown ranged from 2-5’, but it’s hard to gauge how wide it was, because it covered a lot of elevations. I think there is considerable overlap with the large slide that ran there earlier this season. We did not observe any other slides, collapsing, or cracking, but the wind did pick up in the early afternoon." 


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Northern Gallatin
Mt Blackmore
Natural avalanche on Blackmore east face
Incident details include images
Incident details contain video
Mt Blackmore
HS-N-R4-D3-O
Elevation: 9,600
Aspect: NE
Coordinates: 45.4431, -110.9990
Caught: 0 ; Buried: 0

From email: "I toured into Blackmore [2/19/21] and observed an old snow avalanche at 9600' on the east face of Mt Blackmore. I was there the day before and didn't see any evidence of avalanche activity; strong overnight winds with ample snow available for transport appeared to be enough to tip the scales."


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Northern Gallatin
Maid of the Mist
Natural avalanche below Maid of the Mist
Incident details include images
Maid of the Mist
SS-N-R4-D2
Elevation: 8,400
Aspect: E
Coordinates: 45.4164, -110.9700
Caught: 0 ; Buried: 0

An ice climber in Hyalite reported a natural D2 underneath the Maid today. Looked like it ran yesterday (2/18/21).


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Cooke City
Crown Butte
Snowmobile Triggered Slide on Crown Butte
Incident details include images
Crown Butte
SS-AMu-R2-D2
Coordinates: 45.0525, -109.9620
Caught: 0 ; Buried: 0

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


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Bridger Peak
Natural Avalanche South of Saddle Peak
Incident details include images
Bridger Peak
HS-NC-R3-D2.5-O
Elevation: 8,500
Aspect: SE
Coordinates: 45.7701, -110.9400
Caught: 0 ; Buried: 0

From email: "I just watched this slide from my house on Jackson Creek. It’s south of Saddle Peak."


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Bridger Range
Saddle Peak
Natural New snow slabs, cornice falls, dry loose in south Bridgers
Saddle Peak
SS-N-R1-D2-S
Elevation: 8,800
Aspect: E
Coordinates: 45.7943, -110.9360
Caught: 0 ; Buried: 0

2/18/21 at 11:45 GNFAC forecaster observed with binoculars natural avalanche activity within new snow along ridgeline south of Bridger ski area to Bridger peak. There were two 50-100 foot wide slabs that broke in the recent storm snow, in the Pinnacles and on Bridger Peak. Wind was blowing strong from the west and there was a lot of snow transport. Cornices were very large and some had broke and gouged through the recent new snow and ran long distances a few triggered broader loose snow avalanches. 


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Cooke City
Fisher Mtn.
Wind Slab, Fisher Mountain
Incident details include images
Incident details contain video
Fisher Mtn.
SS-N-R1-D1-S
Elevation: 10,000
Aspect: E
Coordinates: 45.0661, -109.9590
Caught: 0 ; Buried: 0

Small wind-slab avalanche on the shoulder of Fisher Mountain. 


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Bridger Range
Olson Creek
Snowmobile triggered road cut in Olson Creek
Incident details include images
Olson Creek
SS-AMr-R0-D1
Coordinates: 45.8029, -110.8430
Caught: 0 ; Buried: 0

I triggered a small avalanche along the trail up Olson Creek in the Bangtails. It cracked about 75 feet wide, but only a small amount actually slid.


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Southern Madison
Hebgen Lake
Collapsing Near Hebgen Lake
Hebgen Lake
Coordinates: 44.8381, -111.3430
Caught: 0 ; Buried: 0

From Obs: "Observed a dozen or more collapses while skinning up south-facing aspect between 7500 and 8300ft. Noted shallow snow depth of 2-3ft where collapses were occurring."


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Northern Gallatin
Divide Peak
Very Large, Natural Avalanches Divide Basin
Incident details include images
Divide Peak
HS-R4-D3
Elevation: 9,800
Coordinates: 45.3925, -110.9760
Caught: 0 ; Buried: 0

From Obs: "I skied around the little hills in the basin south of Divide Peak today, and saw quite a bit of recent activity. The southwest corner of Divide Cirque slid on the storm slab and broke 1200-1500’ wide, an east aspect had a crown that exceeded 6’ in places, and the south side of Divide broke 2-6’ deep and ran full track. Things up high are active. I observed no collapsing or cracking, but the signs of instability were still pretty clear"


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Northern Madison
Beehive Basin
Splitboarder triggered, caught and killed in Beehive
Incident details include images
Incident details contain video
Beehive Basin
HS-ARu-R4-D2.5-O
Elevation: 9,100
Aspect: SW
Coordinates: 45.3269, -111.3840
Caught: 2 ; Buried: 1; Killed: 1

On February 14, 2021, two splitboarders triggered an avalanche in Beehive Basin north of Big Sky. They were skinning up the slope when they triggered the avalanche. Both members of the party were caught, but Boarder 1 was able to grab trees and not be buried. Boarder 2 was carried approximately 300 feet downslope where he hit a tree and was critically injured. He was partially buried, entangled around a tree with his head downhill. Boarder 1 heard his partner’s screams, called 911 and went to his aid. He administered first aid and worked to keep him warm and calm. Gallatin County Sheriff Search and Rescue in Big Sky (GCSAR) left the trailhead within 45 minutes of the 911 call, skied to the scene and began providing care. A GCSAR helicopter arrived soon afterward and the injured boarder was short hauled to Big Sky Fire Department and medical care. Boarder 2 died from his injuries that night. The avalanche was 300 feet wide, 500 feet vertical and averaged 2 feet deep. It broke on a layer of facets and near the ground. Read the full accident report here: https://www.mtavalanche.com/accident/21/02/16


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Cooke City
Woody Ridge
Natural Avalanche, West Side Woody Ridge
Incident details include images
Woody Ridge
SS-N-R2-D2
Elevation: 10,000
Aspect: W
Coordinates: 44.9739, -109.9240
Caught: 0 ; Buried: 0

From FB: "Winds moderate out of the west. Saw a recent wind slab natural on NW facing starting zone of tube south of Titanic. Ran into titanic approximately 500' vertical where tubes join. D2 in size."


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Cooke City
Daisy Pass
Snowmobile triggered small slides near Daisy Pass
Incident details include images
Incident details contain video
Daisy Pass
SS-AMu-R1-D1.5
Elevation: 9,950
Aspect: SE
Coordinates: 45.0497, -109.9640
Caught: 0 ; Buried: 0

Saw 2 recent HS-AM-R1-D1 Henderson Ridge, close to Daisy, SE, >35* 9950’ 45.0536, 109.9524


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Southern Madison
Cabin Creek
Snowmobile triggered slides in Cabin Creek
Incident details include images
Cabin Creek
SS-AMu-R3-D2-O
Coordinates: 44.8949, -111.2280
Caught: 0 ; Buried: 0

On 2/13/21 riders reported they triggered this avalanche, and remotely triggered two other slides. Nobody was injured. One partially buried.


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Bridger Range
Wolverine Bowl
Wind slab avalanche north of Bridger
Incident details include images
Wolverine Bowl
SS-R2-D2
Elevation: 8,200
Aspect: E
Coordinates: 45.8301, -110.9340
Caught: 0 ; Buried: 0

On 2/13/21 skiers in the backcountry north of Bridger saw this avalanche occur in wind loaded terrain. They reported a ski track in terrain above, but not sure if it was there already.


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Cooke City
Hayden Creek
Natural slide in Hayden Ck south of Cooke
Hayden Creek
N-R2-D2
Elevation: 10,000
Aspect: NE
Coordinates: 44.9952, -109.9080
Caught: 0 ; Buried: 0

From obs: "Natural slab on Climax. Crown was right below the ridgeline and ran almost to valley floor. R2 D2. Not enough vis for a pic... Point releases in steep terrain on Climax."


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Cooke City
Scotch Bonnet
Small Natural Avalanche, Scotch Bonnet
Incident details include images
Incident details contain video
Scotch Bonnet
SS-N-R1-D1.5-I
Elevation: 10,200
Aspect: NE
Coordinates: 45.0566, -109.9510
Caught: 0 ; Buried: 0

Riders observed a small, natural avalanche on the northeast face of Scotch Bonnet on Saturday. The slide likely occurred on Feb 11 or 12. 


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Southern Madison
Ernie Miller Ridge
Ernie Miller Ridge Naturals
Ernie Miller Ridge
SS-N-R2-D2
Aspect: E
Coordinates: 44.9560, -111.1320
Caught: 0 ; Buried: 0

Skiers at Bacon Rind saw some fresh looking avalanche activity on northern portion of Ernie Miller Ridge on Feb 14. They suspect it was from the last couple of days. 


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Lionhead Range
Lionhead Ridge
Snowmobile Triggered Slide on Lionhead Ridge
Incident details include images
Lionhead Ridge
SS-AMu-R3-D2-O
Elevation: 9,500
Aspect: NE
Coordinates: 44.7145, -111.3180
Caught: 0 ; Buried: 0

Snowmobile triggered slide on Lionhead Ridge in Upper Watkins drainage on 2/11/2021. Appears to have broken on weak snow near the ground. 


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Southern Gallatin
Portal Creek
Remotely triggered avalanches in Portal Creek
Incident details include images
Portal Creek
SS-AMr-R2-D2-O
Coordinates: 45.2890, -111.1410
Caught: 0 ; Buried: 0

On Thursday, Feb 11, snowmobilers remotely triggered two large avalanche in the Portal Creek area.

From obs: "Broke on lookers right crown first then triggered second slide to lookers left (rocks everywhere). Broke on depth hoar on both slides north facing aspects. Nobody was caught."


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Cooke City
Woody Ridge
Natural avalanches on Woody Ridge
Incident details include images
Woody Ridge
SS-N-R2-D2
Coordinates: 44.9739, -109.9240
Caught: 0 ; Buried: 0

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'"

Likely broke following the wind event on 2/9/2021.


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Cooke City
Henderson Bench
Natural avalanche on Henderson Ridge, Cooke City
Incident details include images
Henderson Bench
N-R2-D2
Aspect: NE
Coordinates: 45.0558, -109.9470
Caught: 0 ; Buried: 0

This natural avalanche occurred on a wind loaded, NE aspect above Henderson Bench outside Cooke City. Wind-loading has been the main avalanche concern.


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Cooke City
Mt. Abundance
Large natural avalanche on Mt. Abundance, Cooke
Incident details include images
Mt. Abundance
HS-N-R4-D3
Elevation: 10,000
Aspect: SE
Coordinates: 45.0687, -110.0160
Caught: 0 ; Buried: 0

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.


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Cooke City
Town Hill
Natural Avalanche on Town Hill, Cooke City
Incident details include images
Town Hill
SS-N-R2-D2
Elevation: 8,400
Aspect: SE
Coordinates: 45.0256, -109.9370
Caught: 0 ; Buried: 0

The main gully on Town Hill went naturally last night (2/9) with a 3-4' crown.


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Northern Madison
Middle Basin
Middle Basin Avalanches
Incident details include images
Middle Basin
SS-N-R2-D2-I
Elevation: 9,500
Coordinates: 45.3374, -111.3810
Caught: 0 ; Buried: 0

From email: "Went out in Middle Basin north of Big Sky today and saw 5 separate slides, the largest about 500ft across and approximately 2ft deep. All of them were northeast to southeast aspects from about 9200 to 9800ft. The included photos aren't the best but give an idea of the slides, most are from that largest slide." Photo: B. Richards


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Northern Gallatin
Alex Lowe Peak
Natural, North Face Alex Lowe
Incident details include images
Alex Lowe Peak
HS-N-R3-D2.5-O
Aspect: N
Coordinates: 45.4272, -111.0140
Caught: 0 ; Buried: 0

From Obs: "One large avalanche observed, on the path adjacent to the N Couloir on Alex Lowe. More or less went full path, I would estimate 2m max crown depth. HS-N-R4/D2.5-O. A large cornice fell on the NF of Blackmore with no slab results. Observed several size 1 slabs that failed within new snow during the day on N aspects."


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Northern Madison
Cedar Mtn.
Natural Avalanches on Cedar mountain
Incident details include images
Cedar Mtn.
SS-N-R2-D3-O
Elevation: 9,600
Coordinates: 45.2268, -111.5120
Caught: 0 ; Buried: 0

I observed 4 avalanches that broke at a variety of aspects and elevations on Cedar Mountain during the tail end of the storm, likely Feb. 5-8, 2021


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Northern Madison
Buck Ridge
Many Natural Avalanches - Muddy Creek
Incident details include images
Buck Ridge
SS-N-R2-D2
Elevation: 8,400
Coordinates: 45.1719, -111.3800
Caught: 0 ; Buried: 0

I counted 11 natural avalanches in Muddy Creek that failed during the tail end of the storm. They mostly appear to be storm slab avalanches, but some may have broken deeper. 


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Northern Madison
Buck Ridge
Many natural avalanches on Buck Ridge
Incident details include images
Incident details contain video
Buck Ridge
SS-N
Coordinates: 45.1719, -111.3800
Caught: 0 ; Buried: 0

We (GNFAC) observed many (6+) natural avalanches while riding on Buck Ridge. Many looked to be breaking under the storm snow (3+feet; 2.7" SWE), but some looked deeper. We deduced that these ran on Monday, 8 February, because there was only a few inches of snow covering the debris.


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Cooke City
COOKE CITY
Cooke City Soft Slabs
Incident details include images
COOKE CITY
SS-R1-D1.5
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

From IG Stories: Two avalanches east of Cooke City above Hwy 212. Just west of the state line. 


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Bridger Range
The Ramp
Small Avalanches, Ramp
Incident details include images
The Ramp
SS-N-R1-D1
Elevation: 8,350
Aspect: NE
Coordinates: 45.8288, -110.9310
Caught: 0 ; Buried: 0

From email: "Skied the ramp outside of Bridger Bowl today, saw these small NE facing crowns at 8350'. We also experienced localized cracking while skinning at the density change interface of the new and "old" snow (8-12" at this elevation by 4pm). No other observed avalanches, no other cracking and no collapsing."


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Cooke City
Sheep Creek
Sheep Creek - Gully east of Miller Trees
Incident details include images
Sheep Creek
SS-ASu-I
Elevation: 9,100
Aspect: E
Coordinates: 45.0396, -109.9750
Caught: 0 ; Buried: 0

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 slide 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)."


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Northern Madison
Yellowstone Club
Remote Trigger Outside of YC
Incident details include images
Yellowstone Club
ASu-R3-D2-O
Elevation: 8,000
Aspect: NE
Coordinates: 45.2311, -111.4410
Caught: 0 ; Buried: 0

This avalanche was triggered from across the boundary line of the YC. 


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Northern Madison
Beehive Basin
Natural avalanche in Beehive Basin
Incident details include images
Beehive Basin
SS-N-R2-D2
Coordinates: 45.3407, -111.3910
Caught: 0 ; Buried: 0

Natural avalanche on an east aspect in Beehive Basin. Likely broke during the avalanche warning on 2/7/2021. Appears to have broken ~4ft deep on weak snow near the ground.


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Lionhead Range
Watkins Creek
Natural Avalanche on Lionhead Ridge
Incident details include images
Watkins Creek
SS-N-R3-D2
Coordinates: 44.7536, -111.3300
Caught: 0 ; Buried: 0

Natural avalanche on Lionhead Ridge in upper Watkins Creek. Likely broke on Sunday 2/7. Appears to have failed on weak snow near the ground.


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Southern Madison
Skyline Ridge
Multiple avalanche on Skyline Ridge
Incident details include images
Skyline Ridge
SS-N-R2-D2.5
Coordinates: 44.9205, -111.2300
Caught: 0 ; Buried: 0

Multiple large natural avalanches ran on Skyline Ridge, on the side facing Cabin Creek and the side facing Teepee/Bacon Rind Creeks. They likely broke during the avalanche warning on Sunday, Feb 7th. One slide on the Cabin Creek side of the ridge ran within 300 ft of the Big Sky Trail. Many of the slides appear to have broken on weak layers near the ground. 


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Northern Madison
Yellow Mountain
Natural Avalanches, Yellow Mountain
Incident details include images
Yellow Mountain
SS-N-R2-D2
Coordinates: 45.2995, -111.3200
Caught: 0 ; Buried: 0

A Big Sky resident spotted 5 natural avalanches on Yellow Mountain that failed during the tail end of the storm. 


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Northern Gallatin
Mt Ellis
Widespread Cracking on Mt Ellis
Incident details include images
Mt Ellis
Coordinates: 45.5777, -110.9550
Caught: 0 ; Buried: 0

We saw widespread cracking on several steep slopes on Mount Ellis. 20"+ of new snow loaded a weak snowpack. 


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Northern Madison
Dudley Creek
Dudley Creek
Incident details include images
Dudley Creek
SS-N-R2-D2-O
Elevation: 8,500
Aspect: N
Coordinates: 45.3145, -111.2950
Caught: 0 ; Buried: 0

Skiers in Dudley Creek saw recent avalanche in the north facing glades 


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Out of Advisory Area
Other place
Natural new snow slabs in YNP near Cooke
Incident details include images
Other place
SS-N-R2-D2
Elevation: 8,500
Coordinates: 45.6553, -110.5580
Caught: 0 ; Buried: 0

These slides were observed in Yellowstone National Park on 2/7/21.


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Northern Madison
Yellowstone Club
Large explosive triggered, and naturals on road cuts, at Y.C.
Incident details include images
Yellowstone Club
HS-AEc-R5-D3-O
Coordinates: 45.2311, -111.4410
Caught: 0 ; Buried: 0

From YCSP: "We’ve had more snow and SWE in the past 5 days than we had in all of January. Avalanche mitigation today produced avalanches running full path at the new snow/old snow interface for most of our paths.... Some of our lower ridge avalanche terrain climaxed for the 2nd time this season. Our first round of mitigation got a few paths to climax, but the teams didn’t feel confident with the initial results.... They went back out with more explosives and were able to produce an avalanche that ran 400’ wide, with a 6-10’ crown, running close to the ground. This is wind loaded terrain. It’s also perhaps the largest crown I’ve seen on these paths and one of the few times I’ve seen it climax more than once.

I took a drive at the end of the day and captured a few photos of road cuts at the YC that slid today."


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Northern Madison
Cedar Mtn.
Natural avalanche on Cedar Mtn.
Incident details include images
Cedar Mtn.
U-N-R2-D2-U
Aspect: E
Coordinates: 45.2268, -111.5120
Caught: 0 ; Buried: 0

A patroller a the YC saw a slide on some of Cedar Mountain’s lower east facing terrain on 2/7/21.


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Bridger Range
Bostwick Creek
Natural avalanche in Y-couloir west side Bridgers
Incident details include images
Bostwick Creek
HS-N-R2-D2-O
Elevation: 8,700
Aspect: NW
Coordinates: 45.7976, -110.9380
Caught: 0 ; Buried: 0

Ski patrol had brief visibility on 2/7/21 to see a large natural avalanche, believed to have ran 2/7/21, on the northwest slopes of Saddle Peak on the West Side of the Bridger Range.


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Southern Madison
Specimen Creek
Natural avalanahce (and collapsing) Specimen Creek
Specimen Creek
N-R4-D2
Elevation: 8,500
Aspect: SW
Coordinates: 45.0265, -111.0480
Caught: 0 ; Buried: 0

From obs: "GNFAC, You’re never going to believe this, but there was tons of whumphing up in Specimen Creek today! There were a few avalanche classes there digging snow pits and getting unstable test results by the sounds of it. We saw a good sized natural on a steep SW facing meadow around 8500’, probably would call it R4D2 but it was hard to get a good look through the storm."


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Northern Madison
Beehive Basin
Skier triggered test slope (and collapses) Beehive
Incident details include images
Beehive Basin
SS-ASc-R4-D2-O
Elevation: 8,000
Aspect: W
Coordinates: 45.3407, -111.3910
Caught: 0 ; Buried: 0

On 2/7/21 skiers in Beehive reported: "Numerous large collapses, ECTP in several pits on mid-pack facets, and triggered a test slope remotely from flat terrain. It broke in the old snow, but towards to top, maybe 10cm below the interface with the last week’s snow. Propagated over 50m, crown depth 60-100 cm. Would be solid size 2 if the slope wasn’t 20m tall."


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Cooke City
COOKE CITY
Natural Avalanches West of Cooke City
Incident details include images
COOKE CITY
SS-N
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

Skiers observed several natural avalanches west of Cooke City. All were on wind-loaded slopes. Varying size and destructive potential. 


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Bridger Range
Bridger Peak
Natural avalanches along Bridger Ridge
Incident details include images
Bridger Peak
HS-N-R3-D2.5-O
Elevation: 8,600
Aspect: NE
Coordinates: 45.7701, -110.9400
Caught: 0 ; Buried: 0

Seen on 2/9/21: Many natural avalanche crowns along the Bridger Ridge that ran during the storm from 2/4-2/8, likely between 2/5-2/7. Across all of Bridger Peak, some on Baldy Peak, Many through The Pinnacles, Argentina Bowl and Saddle.


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Bridger Range
BRIDGER RANGE
Skier remote triggered small slab, N. Bridgers
Incident details include images
BRIDGER RANGE
SS-ASr-R3-D1.5-G
Coordinates: 45.8512, -110.9480
Caught: 0 ; Buried: 0

Skiers sent an IG post saying they remote triggered this slide from the adjacent road on 2/6/21.


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Lionhead Range
LIONHEAD AREA
Snowmobile triggered near Lionhead
Incident details include images
LIONHEAD AREA
SS-AMu-R3-D2-I
Elevation: 8,000
Aspect: S
Coordinates: 44.7292, -111.3230
Caught: 0 ; Buried: 0

Riders wrote that they triggerend an avalanche on a south facing slope in West Targhee Creek on 2/6/21. No one was caught.


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Bridger Range
Ross Peak
Whumphing and small dry loose slides near Ross Peak
Ross Peak
Coordinates: 45.8586, -110.9560
Caught: 0 ; Buried: 0

From skiers obs 2/6/21: "Observations for 6600’ to 8300’, E and NE aspects [near Ross Peak]: - Saw several natural dry loose avalanches (D1) on upper NE face of Ross - No slab avalanches observed - Observed at least two dozen whumphs (mostly small and localized) while skinning - no cracking - winds were steady moderate in the afternoon, lots of blowing and drifting snow observed; winds primarily from W but also NW and N - average ski pen around 30 cm"


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Southern Gallatin
Specimen Creek
Collapses and small remote triggered avalanche specimen crk
Incident details include images
Specimen Creek
Coordinates: 45.0265, -111.0480
Caught: 0 ; Buried: 0

From Obs: "Big whumf a cracking on south east slope 8000 feet elevation. sub 25 degrees angle. Super loud and scary when it fractured. Broke to the ground. Small crown up higher on same slope." 

A separate group wrote: "We got 5-6 good whumphs while skinning around. It was snowing S-1 all day with light winds. We saw a group skiing a low angle ridge with a fresh crown off to the side of the ridge where it’s steeper, maybe 10-20’ from their tracks. It looked very much like they remote triggered it but I can’t be sure. The slide was R1D1.5, definitely broke into old snow."


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Cooke City
Hayden Creek
Skier triggered slide from cornice, Cooke
Hayden Creek
U-AS
Elevation: 9,800
Aspect: E
Coordinates: 44.9952, -109.9080
Caught: 0 ; Buried: 0

From a skier: "as we were digging a pit, we got into a conversation with three skiers as they skinned past. They had skinned up Rip Curl (from Hayden Creek) and then continued S. along Woody Ridge. They experienced several large collapses along the ridge line and eventually remotely triggered a cornice collapse that set off an avalanche (described as a large powder cloud) in the Climax slide path (E. aspect)."


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Bridger Range
Wolverine Bowl
Small Natural Avalanches north of Bridger
Incident details include images
Wolverine Bowl
N-R1-D1.5
Elevation: 7,900
Coordinates: 45.8301, -110.9340
Caught: 0 ; Buried: 0

Signs of a small natural avalanche on lower wolverine bowl and north Bradley's.


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Northern Gallatin
Hyalite - main fork
Natural below Maid of the Mist
Incident details include images
Hyalite - main fork
N-R2-D1.5
Elevation: 8,000
Aspect: NE
Coordinates: 45.4175, -110.9660
Caught: 0 ; Buried: 0

Natural slide below Maid of the Mist (unless someone was up climbing Maid No More...). E/NE aspect, roughly 8000' elevation. Looked to have run last night or early this morning. Poor resolution iphone photo, but gets the job done. Photo taken from the base of the Dribbles.


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Bridger Range
Saddle Peak
Large Natural avalanches on Saddle Peak and Truman Gulch
Incident details include images
Saddle Peak
HS-N-R3-D2.5-O
Elevation: 9,000
Aspect: NE
Coordinates: 45.7943, -110.9360
Caught: 0 ; Buried: 0

From BBSP on 2/6/21" "Clear vis gave us a good view of  natural avalanches on Saddle peak , the Football field and Behind D-rtand the nose on Truman Gulch that ran yesterday morning (2/5/21)"


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Northern Gallatin
Divide Cirque
Large natural avalanche in Divide cirque
Incident details include images
Divide Cirque
HS-N-R3-D2.5-O
Coordinates: 45.3934, -110.9690
Caught: 0 ; Buried: 0

From skier in Divide Cirque on 2/6/2021: "In the basin, between pt 10,201 and 10,024 there was a very large avalanche that must have slid yesterday or last night. It looks like it propagated at least 1000’ wide and at the deepest the crown was easily 5 feet. Visibility was low so it was hard to tell, but it was definitely a big slide."


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Southern Madison
Bacon Rind
Whumpfs at Bacon Rind
Bacon Rind
Coordinates: 44.9609, -111.1000
Caught: 0 ; Buried: 0

Skiers at Bacon Rind had the snowpack whumpf several times while skinning.


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Bridger Range
Fairy Lake
Natural avalanche near Fairy Lake
Incident details include images
Fairy Lake
SS-N-R2-D2
Coordinates: 45.9043, -110.9580
Caught: 0 ; Buried: 0

Natural avalanche observed near Fairy Lake on 2/6/21. 150ft wide and varying from 2.5-5ft deep. Broke in the new snow but also stepped down to near the ground.


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Southern Gallatin
Specimen Creek
Whumpfs and cracks in Specimen Creek
Specimen Creek
Elevation: 7,500
Coordinates: 45.0265, -111.0480
Caught: 0 ; Buried: 0

S2 snow most of the day. Light winds, overcast. Extensive large whumpfs and cracks at about 7000-7800 feet. Snow was unsupportable in many places, others had a clear slab in the midpack you could feel with a pole probe. Dug a pit at 7500 ft on east aspect...Bottom 30cm was large facets bordering on depth hoar. Clear cups forming and 3-4mm or so (F). CT18. ECTX, which surprised me... I should have done a second test. Was able to propagate on the depth hoar using a snow saw easily, though did not perform full PST.


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Cooke City
Woody Ridge
Skier triggered and partially buried on Woody Ridge
Incident details include images
Woody Ridge
SS-ASu-R2-D2-I
Elevation: 9,000
Aspect: NE
Coordinates: 44.9739, -109.9240
Caught: 1 ; Buried: 0

A 100’ wide by 12”-24” deep avalanche was triggered by a skier on a North East aspect of Woody Ridge at 9000’. From reporting group: "Skier was carried and partially buried after arresting on a tree. The area was short pitches with rollovers and pillow/shelf features. Once the skier was in avalanche terrain the wind loaded storm slab released exposing a faceted layer which the new snow had not bound with. The release occurred where the slope went from 20 degrees to 30 degree terrain. A pit dug the previous day (2/4/2020) on the same slope resulted in an ECT 50 + and a CT 38. Afterward that day we proceeded up the ridge to find wind slabs formed at the top of the ridge which would release when cut. Today, the snow felt stable on the ascent through trees and on tree covered ridges. When we turned around in what we considered “mellow”/“putt putt” terrain due to an intensifying storm and the day becoming late we skied through some exposed ridges and drops. First skier saw no avalanche activity through broken up terrain. Second skier triggered the slide on the first turn. After the event a third skier skied the tree covered ridge used for the ascent and was clear. Whompfing was observed in the trees below the pillows after the event..."


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Bridger Range
Saddle Peak
Small natural slide on Saddle Peak
Saddle Peak
SS-N-R1-D1.5
Elevation: 8,900
Aspect: NE
Coordinates: 45.7943, -110.9360
Caught: 0 ; Buried: 0

Bridger Bowl ski patrol noted natural avalanche debris below the cliffs of Saddle Peak. It appeared to involve only the new snow, but started high on the face and ran over the cliffs with a decent debris pile below going home chute.


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Southern Gallatin
Fawn Pass
Several large whumpfs on way to Fawn Pass, YNP
Fawn Pass
Coordinates: 44.9282, -110.9140
Caught: 0 ; Buried: 0

We skinned out from Fawn Pass trailhead into the Fan Creek drainage, and eventually headed up and across a small ridge. We experienced several large whumps, specifically on flat ground in lightly treed areas, some of which resonated out roughly a few hundred yards, and shook snow off of small trees. Had a few isolated but large/loud collapses on ~20 degree slopes as well. No cracking or propagation followed that we could see. No recent signs of avalanche activity in the area, and we tried to loose something from a few test slopes with no success. South aspects were becoming very crusty in the warm sunshine today.


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Lionhead Range
LIONHEAD AREA
Snowmobiler triggered avalanche, Lionhead
Incident details include images
LIONHEAD AREA
SS-AMu-R2-D2-O
Elevation: 9,400
Aspect: SE
Coordinates: 44.7310, -111.3880
Caught: 0 ; Buried: 0

A snowmobiler triggered this avalanche, no one was caught. From the reporting party, "We were playing in the trees below the ridge and we climbed up to the left in that little meadow and that's when the slide broke to our right and propagated up. From what I can tell is it broke on two layers and it was approximately 100ft wide and ran 500ft. Debris piled up in the trees above the meadow we were playing in."


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Southern Gallatin
Specimen Creek
Meldrum Peak Natural Avalanche
Incident details include images
Specimen Creek
SS-N-R2-D2
Coordinates: 45.0265, -111.0480
Caught: 0 ; Buried: 0

From obs on 2/1: "Got lots of whumphs, probably 20+. Saw an avalanche on the west face of Meldrum, looked to be a few days old, but probably R2D2."


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Lionhead Range
LIONHEAD AREA
Major avalanche cycle
Incident details include images
Incident details contain video
LIONHEAD AREA
SS-N
Coordinates: 44.7292, -111.3230
Caught: 0 ; Buried: 0

From GNFAC field day on 2/1:

Many natural avalanches were triggered by a large snowstorm that dropped 2 feet of snow on 1/29 and 1/30. The slides broke on numerous weak layers: under the snow, a surface hoar layer mid-pack and sugary facets at the ground (depth hoar).


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Cooke City
Republic Mountain
Natural Avalanche, Fin
Incident details include images
Republic Mountain
SS-N-R2-D2.5-O
Elevation: 9,800
Aspect: E
Coordinates: 45.0045, -109.9570
Caught: 0 ; Buried: 0

A large natural avalanche on the Fin outside of Cooke City was observed on January 31st. It likely failed on January 30th. 


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Southern Madison
Taylor Fork
Natural avalanche on Woodward Mountain
Incident details include images
Taylor Fork
HS-N-R3-D3-O
Elevation: 10,400
Aspect: E
Coordinates: 45.0126, -111.4130
Caught: 0 ; Buried: 0

We saw this crown while riding in Taylor Fork on 1/31/21.


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Southern Madison
Taylor Fork
Natural and snowmobile triggered avalanches in Taylor Fork
Incident details include images
Incident details contain video
Taylor Fork
SS-N-R2-D2-O
Coordinates: 44.9645, -111.3340
Caught: 0 ; Buried: 0

GNFAC forecaster were in Taylor Fork on 1/31/21: There were many small(er) pockets R2-D1/2 along the northeast facing ridge of Carrot and Sage Basins. Some looked like they broke below the new snow or on surface hoar, and some broke deeper to the facets at the ground. We dug a pit above one of the crowns that and got an ECTP16 on surface hoar 40 cm down, and ECTN 29 on the depth hoar. PST 37/120 end on the depth hoar. HS 150cm. 

Also numerous slides in Lightning and Beaver Creeks in the Wilderness. Also noticed a large crown in Sunlight Basin spanning across the lookers left half of the heavily wind-loaded/corniced bowl. R3-D2/2.5 probably, 500’+ wide


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Cooke City
Meridian Peak
many small remote triggered slabs near Cooke
Incident details include images
Meridian Peak
SS-ASr-R2-D1-I
Elevation: 9,000
Coordinates: 45.0195, -110.0080
Caught: 0 ; Buried: 0

SS-ASr-R2-D1-I SE Aspect, 9000 feet, 35-40 degrees Remotely triggered from tracks visible on right side of photo. This photo shows one of five similar remotely triggered avalanches today in the Silver Creek drainage and 9595 Glades. All five avalanches released from 35-40 degree rollovers at the interface beneath ~20cm of new snow and were all size D1. The five avalanches spanned from 8500-9500 feet elevation on SE, S, SW, and NW aspects. No activity (e.g. wumphing, cracking, avalanches) was observed below the new-old snow interface.


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Cooke City
COOKE CITY
Natural avalanches near Cooke City
Incident details include images
COOKE CITY
SS-N-R2-D2-I
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

Photo: "Avalanche in Star Creek (sorry for the poor quality, small window of clear weather) From our point of view it looked like storm snow."

South of town skier saw: "R1-D1 50' wide 1-2' deep wind slab that avalanched off of the S portion of Climax Bowl near the ridge line. It also triggered another isolated pocket 200' down in the track that was about 25' wide and looked to be no more than 1' deep. It then entrained all of the new snow and washed over the cliff band that runs through midline resulting in a substantial powder cloud and subsequent debris pile."

Another group reported: "We observed some fresh slab avalanches today around Cooke City.  (about 5 slab avalanches observed). Most of the slides looked to have occured last night or early this am, and involved just new snow 12-18" deep.  All of the slides observed were on SE aspects, with some propagating about 150' wide."

A third group northwest of Cooke City reported: "Slides were seen on all aspects, mid and upper elevations.  Some stepped down into older persistent weak layers.  Observed about 15 fresh slab avalanches."


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Northern Madison
NORTHERN MADISON RANGE
Avalanche on Yellow Mountain
Incident details include images
NORTHERN MADISON RANGE
Coordinates: 45.3023, -111.3260
Caught: 0 ; Buried: 0

From obs: "While driving down the spur road in Big Sky, I noticed this small avalanche on the SW face of Yellow Mountain around 3:30pm"


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Northern Gallatin
Maid of the Mist
Natural avalanche in Maid of the Mist
Incident details include images
Maid of the Mist
N-R2-D2
Elevation: 9,500
Aspect: E
Coordinates: 45.4164, -110.9700
Caught: 0 ; Buried: 0

A natural avalanche occurred on an East aspect in the Maid of the Mist basin. It appeared to have slid last night/this morning. Visibility made it difficult to determine the extent of the debris or the depth of the crown.


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Southern Madison
Ernie Miller Ridge
Skiers remote triggered very large slide Ernest Miller Ridge
Incident details include images
Ernie Miller Ridge
HS-ASr-R4-D2.5-O
Elevation: 9,700
Aspect: E
Coordinates: 44.9560, -111.1320
Caught: 0 ; Buried: 0

From group: "We skinned into the Ernest Miller Ridge area this morning around 8:40am. There was 18-24 inches of fresh storm snow in the bacon rind creek area. As we skinned in, we observed whoomphing and cracking throughout the basin. We ascended right of the normal trail in mellower terrain to the lower bench area. We took a break there and after discussion of the terrain and safe areas to ascend were getting ready to head to the far lookers left trees. A giant collapse happened as we were standing there and sent an almost shockwave like effect up the hill, small ripples and cracks formed way above and away from us and the entire face of Ernest Miller Ridge ripped out and ran the distance of the ridge. We were out of the way of any runout zone and away from the face so in a safe space. It was the largest remote trigger that I have ever experienced and witnessed out in the field."

"Where we triggered the slide, the slope was about 24 degrees, it then triggers on 30ish degrees and then sent the rest of the basin."


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Southern Gallatin
Specimen Creek
Widespread, large collapses shaking trees in S. Gallatin
Incident details include images
Incident details contain video
Specimen Creek
Coordinates: 45.0265, -111.0480
Caught: 0 ; Buried: 0

Skiers in Specimen Creek wrote: "Lots of shooting cracks. Snow was falling off trees hundreds of feet away with some collapses."

Skiers at Bacon Rind reported: "Witnessed two huge whumpfs while skinning a NE aspect around 7600’ en route to regaining the main skin track ridge. Both whumpfs shook the snow off trees within a 100 yard radius."

Another group wrote: "Tremendous amounts of collapsing and whumphing today in the bacon rind. We parked at the southern lot and skinned up the ridge; got collapsing and whumphing on most aspects and all elevations."


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Northern Gallatin
Flanders Creek
Large natural sluffs in Flanders/Hyalite
Incident details include images
Incident details contain video
Flanders Creek
L-N-R2-D1-I
Elevation: 9,000
Coordinates: 45.4483, -110.9370
Caught: 0 ; Buried: 0

From notes: "There was about 6" of new snow in Flanders. It snowed on and off all morning and kicked in again around noon. There was no wind. We climbed Killer Pillar (E. facing, ~8600'). In about a 45 minute span we had 5-6 large sluffs barrel over the top of the climb and run a few hundred feet down the gully...a long ways... It was running so fast and far I had to stop and dig a quick pit to see why. It was near-surface faceting under the snow... LS-N-R2-D,... by the time they all ran I imagine a lot of the bowl above had released. I was super psyched that we both had our lighweight shovels and probes and were beeping. You just never know!"


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Northern Madison
Beehive Basin
Natural Avalanches in Beehive
Incident details include images
Beehive Basin
SS-N-R2-D1-I
Elevation: 9,000
Aspect: W
Coordinates: 45.3407, -111.3910
Caught: 0 ; Buried: 0

From obs: "Sometime mid-day the steep rocky terrain above the going home couloir as well as the start zones in Tyler’s avalanched, just new snow, SS-N-D1R2-I. Just guessing about the trigger but didn’t see tracks going in, although there were certainly lots of people around." Photo: Sam H.


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Southern Madison
Carrot Basin
Whumphing and natural avalanches at Taylor Fork
Incident details include images
Carrot Basin
Coordinates: 44.9592, -111.3130
Caught: 0 ; Buried: 0

Riders in Taylor Fork and Cabin Creek reported cracking and whumphing in the new snow, and another group reported "some big avalanches out near the 'Beaver Slide'... north aspect and steep terrain. Pretty much all the snow to the ground."


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Northern Madison
Dudley Creek
Skier triggered slides N. Madison
Incident details include images
Dudley Creek
SS-AS-R3-D2-O
Aspect: NE
Coordinates: 45.2892, -111.2960
Caught: 0 ; Buried: 0

The NE facing slopes of Dudley Creek are struggling to hold the new snow. I easily triggered the 6-8" of new and windblown snow but it is also stepping down to the facets buried deeper.


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Southern Gallatin
SOUTHERN GALLATIN RANGE
Large Collapses in S. Gallatin
Incident details include images
SOUTHERN GALLATIN RANGE
Coordinates: 45.0432, -110.9620
Caught: 0 ; Buried: 0

From obs: "While skiing a loaded east aspect in the Southern Gallatin, my partner got a large collapse as he started to break trail back to our skin track, cracks shot 20ish feet uphill."


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Southern Madison
Taylor Fork
Snowmobile Triggered Avalanche, Sunlight Basin
Incident details include images
Taylor Fork
SS-AKu-R2-D2-O
Elevation: 8,800
Aspect: N
Coordinates: 44.9695, -111.2920
Caught: 0 ; Buried: 0

A snowmobiler triggered an avalanche while side-hilling. No one caught or injured. The debris was estimated to be 8' deep. 


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Bridger Range
The Throne
Loose Dry Avalanches on the Throne
Incident details include images
The Throne
L-N-R1-D1-I
Elevation: 8,000
Coordinates: 45.8822, -110.9520
Caught: 0 ; Buried: 0

Multiple small dry looses all across the throne. Sliding on a thin sun crust with overlying near surface facets buried 15-25 cms down. None stepped down to deeper layers.


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Cooke City
COOKE CITY
Snowmobiler caught and uninjured in avalanche, Cooke City
Incident details include images
COOKE CITY
AMu
Aspect: S
Coordinates: 45.0202, -109.9380
Caught: 1 ; Buried: 0

CCMS called and said a rider triggered a slide about 1/4 mile north of Huckelberry Lake on a south facing slope. It trashed a rental sled. The rider was at the crown when it broke and was above most of the debris. He was only buried to his knees and was uninjured. No details on size or depth of slide. A close call.
 


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Southern Madison
Ernie Miller Ridge
Natural Avalanche Ernie Miller Ridge
Incident details include images
Ernie Miller Ridge
SS-N-R2-D2-O
Aspect: E
Coordinates: 44.9560, -111.1320
Caught: 0 ; Buried: 0

Skiers reported a natural avalanche on Ernie Miller Ridge. Occurred with minimal new snow on a layer of weak depth hoar


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Cooke City
Sheep Mountain
Snowmobile triggered on Sheep Mtn, Cooke
Incident details include images
Incident details contain video
Sheep Mountain
SS-AMu-R2-D2-O
Elevation: 9,800
Aspect: S
Coordinates: 45.0722, -109.9280
Caught: 0 ; Buried: 0

Snowmobilers triggered two avalanches on 1/22/2021. A group of 11 were climbing on the southside of Sheep Mountain. The slides were triggered by two separate riders.


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Lionhead Range
LIONHEAD AREA
Natural avalanches near Lionhead Ridge
Incident details include images
LIONHEAD AREA
SS-N-R2-D2-O
Elevation: 9,000
Aspect: SE
Coordinates: 44.7292, -111.3230
Caught: 0 ; Buried: 0

On 1/23/21 we saw a couple recent natural avalanche crown on Bald Peak near Lionhead Ridge. Estimated 2-3 days old.


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Northern Gallatin
Maid of the Mist
Natural avalanches near Maid of the Mist
Incident details include images
Maid of the Mist
SS-N-R1-D1.5
Coordinates: 45.4164, -110.9700
Caught: 0 ; Buried: 0

From skier in Hyalite on 1/23/21: "I observed a couple older (1-2 week) naturals on E/ESE aspects in the Divide basin, and newer (1-3 days) naturals on the NE side of Divide and an east aspect at the head of the Maid of the Mist basin."


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Southern Madison
Tepee Basin
Snowmobiler triggered avalanche in Tepee Basin
Incident details include images
Tepee Basin
SS-AMu-R2-D2-O
Aspect: E
Coordinates: 44.9041, -111.1850
Caught: 0 ; Buried: 0
 
A snowmobiler triggered a slide in ..." Upper Teepee basin where skyline ridge meets up with I believe Bacon Rind at the Lee Metcalf area and set off a decent avalanche. Luckily the snowmobiler was able to get out of the path of the avalanche and nobody was involved. It looked like the crown was 3-4 ft in spots on a heavily wind loaded slope. Also there was old avalanche debris just to the south of this spot on same aspect of slope."

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Cooke City
Republic Creek
Cracking and Collapsing, Cooke City
Republic Creek
Coordinates: 44.9855, -109.9410
Caught: 0 ; Buried: 0

From Obs: "On a W facing slope in dense trees just east of the Republic Creek skin track, 8200" - 9200". Snow was not wind loaded at all. There was a buried weak layer about a foot below the new snow, but the new snow had not formed a slab so stability seemed good. There was one incident of a collapse crossing a small gully at about 40deg, a crack formed but did not slide probably due to no wind loading."


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Cooke City
Sheep Creek
Snowmobile Triggered Avalanche, Sheep Creek
Sheep Creek
SS-AMu
Coordinates: 45.0344, -109.9840
Caught: 0 ; Buried: 0

A group of seven riders in Sheep Creek triggered one avalanche and observed two more. The slide failed 1' deep likely on surface hoar. No one was buried or injured. 


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Cooke City
COOKE CITY
Skier and Snowmobile Triggered Avalanches, Cooke City
Incident details include images
COOKE CITY
SS-AS-R2-O
Elevation: 9,500
Aspect: S
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

A skier near Goose Lake observed two human triggered avalanches, one looked to be skier triggered and one looked to be snowmobile triggered. Solar aspects around 9500'. The skier dug at pit and found at least one failed on buried surface hoar


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Northern Gallatin
Mt Blackmore
Loose Snow and Slab Avalanche, Mt Blackmore
Incident details include images
Mt Blackmore
SS-N-R1-D1
Coordinates: 45.4444, -111.0040
Caught: 0 ; Buried: 0

A skier near Mt Blackmore obsersed two loose snow avalanches on the east face of Blackmore and a small slab avalanche on the north face. Continued active wind-loading


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Northern Madison
Buck Ridge
Snowmobile Triggered Avalanche, Second Yellowmule
Incident details include images
Incident details contain video
Buck Ridge
SS-AM-R1-D1.5
Aspect: N
Coordinates: 45.1719, -111.3800
Caught: 0 ; Buried: 0

Snowmobile triggered avalanche on a north-facing slope in Second Yellowmule. Likely occurred on 1/18. 


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Out of Advisory Area
Pebble Creek - YNP
Shooting cracks near Cooke City
Incident details include images
Pebble Creek - YNP
Coordinates: 45.0254, -110.0310
Caught: 0 ; Buried: 0

From obs: "Extremely touchy snowpack in the pebble creek drainage. Nearly constant collapsing and cracks were shooting very long distances. Snowpack was definitely sending a clear message!"


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Cooke City
COOKE CITY
Ski cut small slide on surface hoar
Incident details include images
COOKE CITY
SS-ASc-R2-D1-O
Aspect: SE
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

Skier intentionally cut a small pocket on s SE slope. It broke 3-4" deep on recently buried surface hoar.


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Cooke City
Scotch Bonnet
Collapse/Crack on Scotch Bonnet
Incident details include images
Scotch Bonnet
Elevation: 10,000
Aspect: SE
Coordinates: 45.0714, -109.9440
Caught: 0 ; Buried: 0

From obs: "While skinning up the south shoulder of Scotch Bonnet, about half way (~10,000 ft.) shooting cracks occurred on convexities and were accompanied by whumpfing. While traversing a slope a crack shot perpendicular to the slope at a convexity about 60 ft. up and the whole slope collapsed. After this we immediately turned around taking the most conservative path. These conditions were not present lower down the slope and a snow pit showed no propagation with only a Q3 fracture on the recent layer of surface hoar. It seemed that the higher elevation and more southern aspect decreased the stability of the recent surface hoar layer. The surface hoar layer was not reactive on more westerly slopes."


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Southern Madison
Taylor Fork
Natural Avalanches, Taylor Fork
Incident details include images
Incident details contain video
Taylor Fork
SS-N-R2-D2
Elevation: 9,000
Coordinates: 45.0607, -111.2720
Caught: 0 ; Buried: 0

There were 10 natural avalanches from Wednesday's snow and wind and event in the Taylor Fork. All were small to medium size. Many broke at the new snow interface, some broke deeper on weak facets near the ground. 


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Southern Gallatin
SOUTHERN GALLATIN RANGE
Natural Avalanche in the S. Gallatin Range
Incident details include images
SOUTHERN GALLATIN RANGE
SS-N
Aspect: E
Coordinates: 45.0432, -110.9620
Caught: 0 ; Buried: 0

From an email obervation:

...widespread avalanche activity.

...central Gallatin Range, a mid elevation easterly aspect.


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Cooke City
COOKE CITY
Small, natural avalanches outside Cooke City
Incident details include images
COOKE CITY
SS-N
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

... 3 photos are from around Cooke City, all viewed from the road today (photos 1 and 3 are westerly aspects).  Photo 2 is a northerly aspect.  All mid elevations.


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Cooke City
Hayden Creek
Natural avalanche south of Cooke
Incident details include images
Hayden Creek
SS-N-R2-D2
Elevation: 10,000
Aspect: E
Coordinates: 44.9952, -109.9080
Caught: 0 ; Buried: 0

Natural avalanche observed on Climax path in Hayden creek on 1/13/21.


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Southern Gallatin
SOUTHERN GALLATIN RANGE
Collapsing, cacking, whumpfs in S. Gallatin
Incident details include images
SOUTHERN GALLATIN RANGE
Coordinates: 45.0432, -110.9620
Caught: 0 ; Buried: 0

"Cracking, collapsing, wumphs in the Southern Gallatin. ECTP 22. West facing, 8200’ non windloaded, 80cm of snow. Broke 50cm deep on depth hoar. Barely a cohesive slab on top but still enough to cause unstable conditions."


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Bridger Range
Bostwick Creek
Natural avalanches on West side of Bridgers
Incident details include images
Bostwick Creek
SS-N
Aspect: W
Coordinates: 45.7976, -110.9380
Caught: 0 ; Buried: 0

From the Bridger Bowl Ski Patrol:

Natural avalanche activity was seen on the Cornice below the Y on Bostwick Drainage and behind the Poma lift in Truman Gulch.


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Northern Madison
Wilson Peak
Near Mt. Wilson -- shooting cracks, whumpfing
Wilson Peak
Coordinates: 45.2844, -111.3280
Caught: 0 ; Buried: 0

"Upside-down snowpack, with a ~1ft strong layer on top of a few inches of weak snow. Significant shooting cracks and whoomphing in areas with deep snow. There was comparatively little snow in the trees -- not enough to cause avalanche concerns. We stayed off high-angle slopes, because of the clear signs of avalanche danger, and the very warm temps."


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Lionhead Range
Lionhead Ridge
Lionhead Ridge natural avalanche
Incident details include images
Lionhead Ridge
SS-N-R2-D1.5-O
Aspect: E
Coordinates: 44.7145, -111.3180
Caught: 0 ; Buried: 0

This natural avalanche likely releaed fron the new snow (about .5" SWE) and strong winds during the day.


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Bridger Range
Saddle Peak
Football Field Avalanche
Incident details include images
Saddle Peak
SS-R2-D2-O
Elevation: 8,600
Aspect: E
Coordinates: 45.7943, -110.9360
Caught: 0 ; Buried: 0

Routine avalanche mitigation within the boundaries of Bridger Bowl sympathetically caused half of the Football Field on Saddle Peak to avalanche immediately south of the boundary. "Debris ran over the cliffs pulling out spindrift cones that were up to 5 ft deep." 

*Note: Ski Patrols do not perform any avalanche mitigation outside ski area boundaries. 


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Northern Gallatin
Hyalite - main fork
Couple large collapses in Hyalite Creek
Hyalite - main fork
Coordinates: 45.4472, -110.9620
Caught: 0 ; Buried: 0

From obs: "While ski touring in the Hyalite Creek Drainage today, my ski partner and I both, at separate times of the day, remote triggered sudden collapses. Each time, we felt the snow collapse underneath our feet, and then heard and felt a deep "whumph". The noise came from the North of us both times, where the slope was slightly steeper (still below about 28 degrees-- not colored with "slope angle shading" layer on caltopo.)."


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Southern Madison
Bacon Rind
Whumphing and old avalanche at Bacon Rind
Incident details include images
Bacon Rind
Coordinates: 44.9609, -111.1000
Caught: 0 ; Buried: 0

From email: "...I found a small piece of this mostly low angle slope to have avalanched, probably from a day or two ago, a handful of older tracks were near it. I measure most of this slope around 26-28 degrees... This is on the farthest south part of the top meadow. An epic amount of whumphs up there, I stopped counting after I got to 10 on my second switch back. Our best one knocked snow out of a tree 100’ away. It feels like remote triggering is a very real possibility. Skies were more overcast than expected. While it never went blue, the sun poked out a little in the afternoon. Cold temps, 0F in the AM, warmed to 24F in the PM. 5-6mm surface hoar everywhere,..." 


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Southern Madison
Ernie Miller Ridge
Widespread Collapsing on Ernest Miller Ridge
Ernie Miller Ridge
Coordinates: 44.9560, -111.1320
Caught: 0 ; Buried: 0

From obs: "We were heading for Ernie Miller Ridge, but got deterred by our group hearing MORE COLLAPSES AND SETTLEMENTS THAN I'VE EVER HEARD IN A SINGLE TRIP, in over 23 years of backcountry skiing. Some in the open, some in the woods. Some small, some HUGE and FAR running. Some heard by the person in front, some by the 4th in our party, some where we were following an old skin track, some where we were in fresh snow. As a group we probably heard 25 over the course of the day. We didn't dig any formal pits, as the snow was telling us all we needed to know. Stay safe out there. Thanks"


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Lionhead Range
Lionhead Ridge
Many snowmobile triggered slides at Lionhead
Incident details include images
Incident details contain video
Lionhead Ridge
SS-AMu-R2-D2-O
Elevation: 9,000
Coordinates: 44.7145, -111.3180
Caught: 0 ; Buried: 0

Many snowmobile triggered avalanches were observed after new snow overloaded a very weak snowpack.


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Cooke City
Woody Ridge
Small natural south of Cooke
Woody Ridge
SS-N-R1-D1-O
Elevation: 10,000
Aspect: NE
Coordinates: 44.9739, -109.9240
Caught: 0 ; Buried: 0

From email: "I was skiing in Hayden Creek yesterday 20210109 with two others. We found widespread poor structure across the E face of the sub with some failure upon isolation down 65-80cm on 2-3mm faceted crystals HS varied from 110-230cm. We also saw one small R1D1 pocket that pulled out seemingly at the same depth as the aforementioned faceted crystals In slightly steeper and rockier terrain. No photo. The avalanche was on a ENE aspect on Hayden Peak."


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Cooke City
COOKE CITY
Skier triggered slide north of Cooke
Incident details include images
COOKE CITY
SS-ASc-R3-D2-O
Elevation: 8,700
Aspect: NW
Coordinates: 45.0839, -109.9690
Caught: 0 ; Buried: 0

From obs: "1/9/21 350pm: 333 deg NNW, broke on ski cut lookers right approx 60 ft across, 200 ft or so total distance to toe of debris. Broke 2.5/3 ft deep on a wind loaded pocket, slid on a firm surface with facets on top."


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Cooke City
Republic Mountain
Skiers triggered small slab on lower Republic Mountain
Incident details include images
Republic Mountain
Elevation: 8,500
Aspect: N
Coordinates: 45.0003, -109.9540
Caught: 0 ; Buried: 0

This activity was reported by an observer in Cooke City on 1/9/20. They watched the group trigger this slide while they skinned up, then they descended from a little bit higher.


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Northern Madison
Buck Ridge
Natural avalanche and wide cracks at Buck Ridge
Incident details include images
Buck Ridge
SS-N-O
Elevation: 9,000
Coordinates: 45.1719, -111.3800
Caught: 0 ; Buried: 0

A rider submitted photos of cracks he triggered as well as a suspected natural avalanche and wide shooting cracks, all observed on 1/9/21.


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Northern Gallatin
Mt Blackmore
collapse at Blackmore
Mt Blackmore
Coordinates: 45.4444, -111.0040
Caught: 0 ; Buried: 0

From email: "Got up to Blackmore way.  I didn’t like the skin track heading up to N ridge but my partner was a little ahead and should of reeled him back... because the main skinner right now is exposed to much of face.   So when caught up we angle lookers right a tidge to gain ridge. Just before the ridge was the disturbing collapse."


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Centennial Range
CENTENNIAL RANGE
Sledder triggered slide and 2 naturals in Centennials
Incident details include images
CENTENNIAL RANGE
SS-AM-R2-D2
Coordinates: 44.5476, -111.5250
Caught: 0 ; Buried: 0

From obs: "...Two natural slab avalanches on north aspect of Reas Peak, one from recent storm and one from previous storm. Photo is from a snowmobile triggered avalanche from 1/9/21, you can see the party and one of the members riding the adjacent slope."


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Cooke City
Goose Creek
Avalanche in Goose Crk near Cooke
Incident details include images
Goose Creek
SS-N-R2-D1.5-O
Elevation: 9,000
Aspect: N
Coordinates: 45.0923, -109.9510
Caught: 0 ; Buried: 0

From email: "We suspect this happened fresh today, we  wonder if those animal tracks coming in from the left triggered it. North facing, 2 ft crown, (I’d guess), about 9k feet, facing Goose Creek. So our friends (while ski cutting) triggered a  very similar slide on this same aspect/elevation mid afternoon today, about 1/4 mile farther west along this ridge, looked to be same depth."


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Lionhead Range
Hebgen Lake
Cracking and Collapsing at Hebgen Lake
Hebgen Lake
Coordinates: 44.8381, -111.3430
Caught: 0 ; Buried: 0

From obs: "Skied Lionhead above Hebgen Lake today. Had cracking and collapsing almost constantly on the ascent and along the ridge line. Stuck to low angle terrain and did not trigger anything that moved. No natural avalanche activity."


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Northern Madison
NORTHERN MADISON RANGE
Collapses and Whumph in N. Madison
NORTHERN MADISON RANGE
Coordinates: 45.2952, -111.4100
Caught: 0 ; Buried: 0

I skied in the Northern Madison range today. We had 3 big whumps/collapses on a NE aspect between 7600 and 8000 feet. Kept the slope angle low so nothing slid. The snowpack was about 80 to 90 cm deep outside of tree cover. The skiing was good quality powder skiing.

We dug a pit on that slope and got an ECTP 23. Not super clean shear quality as it was on the facet layer on the ground.


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Northern Gallatin
Flanders Creek
Skier triggered large slide on Flanders Mountain
Incident details include images
Incident details contain video
Flanders Creek
HS-ASu-R4-D2.5-O
Elevation: 9,800
Aspect: E
Coordinates: 45.4359, -110.9440
Caught: 0 ; Buried: 0

From obs: "We dug a pit and found a really weak snowpack! Regardless of the poor stability result, we proceeded to ski an East facing bowl south of Flanders Mountain knowing that the slope angle was low and only flirted with 30 degrees in some parts of the bowl. We could have chosen to ski the trees further to our left, but after evaluating the consequence associated with skiing the bowl, we decided that the center of the bowl did not pose too big a risk given we skied one at a time. My partner skied first, he skied practically all the way back to the skin track when the slope failed and the entire bowl released. He was pretty well out of the way of danger by the time the bowl began to move. From our perspective, the trigger happened at the bottom of the slope.... The bowl was not the only slope that slid, the avalanche propagated around the ridge and released a slide on the more south-easterly facing aspect just south of the bowl. We tail-tucked and went home glad no one was caught or hurt."

GNFAC forecasters visited the site on 1/11/21. We measured the maximum slope angle in the start zone at 35 degrees with an average slope angle of 33 degrees. The debris in each path was up to 2-3 meters deep. The avalanche broke on a layer of weak faceted snow 70 cm above the ground, and propagated almost 1000 feet wide. The crown was 2-3 feet deep.


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Bridger Range
Texas Meadow
Remotely triggered cracking in Bridgers
Incident details include images
Texas Meadow
Coordinates: 45.8427, -110.9370
Caught: 0 ; Buried: 0

From obs: "the whumpf I had heard previously remotely triggered a series of 7-8 large cracks that ranged from 30-100 feet wide. ... As I carefully descended the meadow, I saw many more cracks throughout the slope from the same remote trigger event. Additionally, I triggered two more significant whumpfs with shooting cracks 10-40 feet wide. We determined our remote trigger was at least 300 feet away from where the snow collapsed and cracked"


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Cooke City
Skier Triggered Avalanche near Meridian Peak
Incident details include images
SS-ASu-R2-D1.5
Elevation: 9,350
Aspect: SE
Coordinates: 45.0270, -110.0030
Caught: 1 ; Buried: 0

From observation (1/8/21): "Skier triggered slide from someone outside our group lower in Silver Creek 9350’ S facing 18-24” deep 60-70’ wide. Ran 500’ skier was able to regain skis and off slab 100’ below initiation."


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Southern Madison
Remote triggered slide Cinnamon Creek
Incident details include images
R2-D2.5
Elevation: 9,000
Aspect: E
Coordinates: 45.1274, -111.2660
Caught: 0 ; Buried: 0

From obs: "Shooting cracks and collapsing on the entire ascent to the Cinnamon Creek Lookout. Remotely triggered a R2-D2.5 on descent. 2-3 foot crown. Slide path was on an East facing slope at 9000ft. Failed on the same persistent weak layer being seen across most regions of the forecast zone."


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Northern Madison
NORTHERN MADISON RANGE
Many whumpfs/Collapses in N. Madison
NORTHERN MADISON RANGE
Coordinates: 45.2938, -111.3210
Caught: 0 ; Buried: 0

From obs (1/8/21): "Loud whoomphs and collapses while skinning uphill, from the car until we turned around about 400ft below the summit. Snowpack felt extremely responsive and we carefully avoided all avalanche terrain."


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Cooke City
The Fin
Skier triggered, caught and injured on The Fin
Incident details include images
Incident details contain video
The Fin
SS-ASu-R2-D2.5-O
Elevation: 9,700
Aspect: E
Coordinates: 45.0046, -109.9580
Caught: 3 ; Buried: 1

FULL AVALANCHE REPORT: https://www.mtavalanche.com/accident/21/01/11

On January 8, 2021 a group of six skiers triggered an avalanche on The Fin on Republic Mountain outside of Cooke City. They were skinning up the slope when they felt the slope collapse and watched cracks propagate 250’ upslope. Three were caught and partially buried. Skier 1 deployed his airbag, was partially buried and able to get himself free. He freed himself from the debris and began a beacon search which led him to see skier 2 who was buried head down with his airway obstructed. He was uncovered by skier 1, not breathing and unconscious. He sustained injuries, but later made it out under his own power. Skier 3 was partially buried higher in the path, sustained serious injuries to his ribs and lungs and was evacuated by helicopter. The avalanche broke 1.5’- 2’ deep, 200’ wide and ran 700’ vertical. The average slope angle was 37 degrees. Slope angle at the crown was 33 degrees on an east aspect at 9,700’ elevation. The avalanche is classified SS-ASu-R2-D2.5-O.


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Cooke City
COOKE CITY
Small Natural Avalanche NW of Cooke
Incident details include images
COOKE CITY
SS-N-R1-D1
Elevation: 9,700
Aspect: E
Coordinates: 45.0202, -109.9380
Caught: 0 ; Buried: 0

Natural avalanche NW of Cooke City on an E, SE aspect around 9,700'.

Photo: B. Fredlund


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Northern Madison
Buck Ridge
Rider triggered large, wide slide on Buck Ridge
Incident details include images
Incident details contain video
Buck Ridge
HS-AMu-R4-D2-O
Elevation: 9,350
Aspect: NE
Coordinates: 45.1719, -111.3800
Caught: 0 ; Buried: 0

We saw this relatively very large, full width avalanches that was triggered on January 7, 2021. It broke on weak, sugary snow below hard wind drifted snow and recent new snow.


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Northern Madison
Buck Ridge
Snowmobile triggered slides (2) on Buck Ridge
Incident details include images
Buck Ridge
HS-AMu-R3-D2-O
Elevation: 9,300
Aspect: NE
Coordinates: 45.1719, -111.3800
Caught: 0 ; Buried: 0

We saw two large snowmobile triggered avalanches (and one very large, in separate record) that occurred on January 7, 2021. They broke on weak, sugary snow below hard wind drifted snow and recent new snow.


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Bridger Range
Fairy Lake
Natural avalanche near Fairy Lake
Incident details include images
Fairy Lake
HS-R2-D2.5
Coordinates: 45.9091, -110.9770
Caught: 0 ; Buried: 0

Large natural avalanche north of Hardscrabble Peak near Fairy Lake. Likely broke during snowfall/wind on Thursday, Jan 7th.


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Northern Madison
Buck Ridge
Many (6) natural avalanches near Buck Ridge
Incident details include images
Buck Ridge
SS-N-R2-D2-O
Elevation: 9,500
Coordinates: 45.1719, -111.3800
Caught: 0 ; Buried: 0

We rode on Buck Ridge on January 8th 2021. We saw six recent natural avalanches and three snowmobile triggered slides. Based on 3-4" of snow that fell yesterday morning covering the debris, we estimate the several natural slides ran 24-48 hours ago. They likely broke on January 6 after the area got 8" of snow on the 5th.


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