Avalanche Activity

From IG: A group of riders noted very wet snow west of Cabin Creek and Southwest of the Taylor Fork. They were sinking to the ground where it was unconsolidated. The group remotely triggered a wet slab avalanche from the ridge top. There were shooting cracks that connected their location to the avalanche. This is an interesting of persistent weak layer and wet snow avalanche problems. 

Saw what looked like a wet slab avalanche from the road along the Madison River.  Roughly north facing slope at 7500'.

From IG: Wet slide to the ground above Quake Lake. 

On sunday 4/14 a large wet loose avalanche ran naturally in closed terrain at Bridger. The larger of the two in the photo, on the right, is from 4/14 at 1230pm. The other slide, on the left, happened yesterday or late in the day Friday.

This afternoon I drove up Bridger canyon to Seitz Rd to see the extent of wet snow activity, and stopped in a few places to look with binoculars. There were many loose wet avalanches that ran over the last 1-3 days. I estimate they involved the upper 6-12" of snow. Activity was widespread and many slides were plenty large enough to be dangerous, but there was nothing especially remarkable about the size and I saw zero wet slabs.

Temperature was 65-70 degrees in the canyon, mostly clear skies with a few clouds, calm to light wind.

From obs: "Natural cornice failure and small slab on Iceberg Peak’s NE face. We skied by the day prior and judging by what the wind did to our tracks overnight, this looked like it happened in the morning."

From obs: " Unintentionally triggered a large cornice collapse on the south face of the Sphinx. " 

Riders saw several natural wet snow avalanches while riding on the west side of the Crazy Mountains. The largest of these was 500' wide, D2. All these avalanches happened in the upper 40cm of the snowpack. 

Driving home from Bridger Bowl I spotted a number of wet loose avalanches in Argentina bowl. It was 1:30 PM when I saw them and the sun was still blazing. I would expect there was more activity as the afternoon progressed.

From IG message: “Rode the banana today.. lots of fast moving sluff. Had a mid elevation pocket pop. New snow seemed to have bonded well, the spot that did pop had formed into 12” slab below rock face. Little to no signs of instability.”

From obs : "After skiing two laps on East facing terrain two basins north of Anger Lake basin and seeing no significant signs of instability, we descended into a north facing gully around 8,200ft and triggered an avalanche on the new snow/old crust interface. The crown was 4-18 inches deep and propagated the entire width of the gully ~40 feet and ran the entire length of the gully ~500 vertical feet. I was able to ski out of the avalanche right as it broke and was not carried. "

While skiing near the ramp we saw several skier-triggered storm slabs and loose snow avalanches. Most were R2/D1.5. The largest of these happened south of the Wolverine Cirque below a cliff band, R2/D2. 

Riders on 04/07/2024 saw a human-triggered avalanche on the shoulder of Hollywood Bowl that was triggered by another party. 

From obs: "Skier triggered slide in one of the Love chutes dropping into Frazier basin. Skier attempted to ski cut the top of the chute, snow was not reactive. He began to ski the chute and triggered a wind slab about 18” deep which failed the crust from the recent warm stretch. Was carried about 200 feet and managed to self arrest on the side of the chute while the slide continued to the bottom. No serious injuries. "

A skier triggered a small avalanche on a steep north-facing pitch, but it did not run far. We saw limited cracking on a layer within the new snow generally 4" to 1 foot deep, and got an ECTP11 on this layer in one of our pits on the east-facing pitch near the standard ski track. Our other pits, one lower on the east face and to the north of the saddle at the top of the Throne, resulted in ECTNs between 5 and 15 on this layer within the new snow.

From IG mesasge (4/6): "Some wet action at arange peak near Sawtell yesterday. From slope Dave and I did our first pit on Monday. Lots of release in that new old interface but didn’t see anything releasing down deeper."

While riding in Lionhead on 04/06/2024 we saw several small wet loose avalanches that likely happened between 04/03-04/04. 

From obs on 04/05/2024: "Toured into Beehive Basin on 04/05/2024. Light freeze overnight ~0.5" crust with wet snow below on most slopes. Treed areas did not freeze. Clouds along with a cold south wind kept many slopes from softening. By 11:30 sunny slopes below 9000' had become wet and made for poor ski conditions. Attached are photos of recent loose wet avalanches that likely happened 24-48 hours ago. All attached photos on SW-W aspects at ~9800'"

We watched several loose snow avalanches occur on south-facing terrain in Frazier basin as early as 10:00 AM. Additionally, we saw many more that had occurred on east facing terrain between 10-11:30. 

From obs: "It likely happened sometime between 10:30 and 1:30 today. It doesn’t look super deep, but it’s hard to say for sure. I’d guess around 2 feet deep." 

On 04/03/2024 we saw several loose wet avalanches that had occurred the day before. Many were small in size (D1) and some larger (D1.5). 

On 4/2/24 we saw a small slab avalanche that occurred since this weekend's snow. It appears to have been triggered by a snowmobile yesterday (4/1/24). It broke 10" to 2 ft deep, 50 ft wide, and ran ~50 vertical feet. It broke on a thin layer of facets beneath the new snow. 

From email: We were out camping around the east side of Sphinx Mountain. We rode sleds over dirt for a while and came from Buck Ridge. We didn’t see any fresh avalanche crowns all weekend. We did get a big whoomph that collapsed the snowpack while skinning along a ridgeline on Sphinx that seemed freshly loaded. Cracks shot out maybe 25 feet around, but it didn’t move. We didn’t dig snow pits; we followed our plan of keeping our terrain selection on the mellow side.

A group of snowmobilers watched a pow surfer trigger an avalanche. The individual was buried to his chest and thankfully uninjured. 

Two rider-triggered avalanches near Reas Peak on north aspects that broke within or just below the new storm snow (D1s)

Natural avalanche broke near Yale Creek on a southern aspect that broke below new snow (D1)

Two natural avalanches that broke within the wind drifted snow in Jefferson Bowl (D2s)

From obs: "Spotted two fresh natural slides, one within Divide cirque on a NE aspect @ ~9,800 (D1, R1), and another on the N face of Hyalite @ ~10,200ft. that was mostly out of view, but could be estimated around similar size and destructiveness. These seem to have occurred within the last 24 hours, or after snowfall, likely windslabs on lee slopes." 

From obs: "Spotted two fresh natural slides, one within Divide cirque on a NE aspect @ ~9,800 (D1, R1), and another on the N face of Hyalite @ ~10,200ft. that was mostly out of view, but could be estimated around similar size and destructiveness. These seem to have occurred within the last 24 hours, or after snowfall, likely windslabs on lee slopes."

A large slab avalanche broke naturally behind the Nose on persistent weak layers. Date estimated. 

We toured up to Flanders Mtn. to take down the weather station for the season (before the road closes on Monday, Apr 1). The main observation is a big, deep 2-6' deep avalanche that broke 300-500' wide in weak snow at the bottom of the snowpack. Photos and video attached. It broke across two separate start zones and included a lower angle ridge (still around 30 degrees) in between that slid. E-NE aspect at 9,800'. HS-N-R3-D3-O. 

On a steep roll, the second skier in our group triggered a small wind slab avalanche. This avalanche was 15-20' wide, 8" deep, and ran for about 30-40 vertical feet. The skier easily skied away from the slide and was not caught. 

From obs: "Spotted this big guy on the east face of Blackmore today. Seemingly natural and I believe it occurred in the last 36 hours or so. Debris had last nights snow on it. I’d estimate it at D2. "

From IG: Very touchy on Hollywood wall this morning. All slopes easily propagated 4-6” deep on a firm bed surface. Most were less than 50’ wide with the exception of the slide in the couloir which propagated down the entire couloir, maybe 500’ wide, and ran through the exits into the main bowl.

From obs: "skiing north of cooke city today observed this Small windslab on a South facing slope ~9800 ft."
 

On our drive home we saw, what I assume were, natural wind-slab avalanches on Quarter Saddle (looked like a cornice collapse) and in Argentina Bowl. Bridger Peak was obscured by heavy wind-loading. There was a small wind-slab release out of Gibbs (I think), I suspect skier triggered, but I could make out a track.

From obs: "Triggered this small windslab while skinning near a steeprollover at the top of an East facing slope above Zimmer Creek. Crown was ~20 ft wide and ran a similar distance. 2"-10" at the deepest."

From obs: "Skied into Frazier basin today. Triggered a few small windslabs and saw a lot of cracking on NW aspects. All windslabs were still small breaking a few inches deep 10-15 feet wide and only running short distances in steep terrain. Winds were strong from the NE all morning and still blowing hard and continuing to load slopes when we left at 12:30. "

From obs: "Saw small avalanches on almost every wind loaded slope out of fairy lake. The one we spotted in the pomp twins had a defined crown roughly 100ft across." 

From obs: "Today (03/26/2024) there were strong winds loading snow onto the Northeast face off of Pine Martin Ridge, just North of Ram Pasture. When we got a better view of the slope, we noticed there had been a natural wind-slab avalanche (left), possibly triggered by a cornice fall. While transitioning, we saw a small part of the same cornice break off and trigger a similar wind slab avalanche (right). "

We saw one new wind-slab avalanche in Sunlight Basin. It was small. From a distance, it appeared to be about 6" deep and 30' across (R1-D1).

A snowboarder intentionally triggered a wind-slab avalanche with a ski cut on town hill in Cooke City. The slide released 6-10” deep and approximately 30’ wide. It ran about 40 vertical feet. 

From obs: "On a small test slope near Muddy Creek we intentionally triggered several small avalanches in wind loaded terrain." 

From obs: "Behind McAtee Basin, we saw a small natural wind slab avalanche on an east facing slope, and we saw a natural wind slab in Bear Creek." 

Collapse with shooting cracks approx 50 feet out

1 skiers boot broke through the crust layer during transitioning and sank to the waist causing collapse of about 2” according to standing skiers feeling of drop

elevation: 9940

Republic side of woody ridge

The notable avalanche activity in the Taylor Fork was a full-depth wet slab avalanche that broke last week during the warm-up on Lightning Ridge. 

From obs. 3/23/24: "Walked out the north gate of bridger to the playground. Just north of Texas meadows observed a slide that ran sometime earlier in the week on a E aspect. Seems to have been triggered naturally by a loose wet coming out of the steep rocky terrain above. Ran about 200 feet was about 50-60 feet wide and crown was roughly 2-3 feet deep. Snow around the slide and on similar aspects was wet in the top 40 cms or so."

Two skiers were ascending a northeast-facing avalanche path on the northernmost ridgeline of Mount Blackmore around 1 PM when they triggered a large, dry slab avalanche that failed 3 feet deep, 150 feet wide, and ran 500 feet vertical. Debris piled up 4-8 feet deep. The avalanche failed on weak, faceted snow near the base of the snowpack. 

As the group was about halfway up the avalanche path, they saw a small slide initiate to their right and then they heard a loud boom as the rest of the slope collapsed 250 feet above them. The skier lower on the path sprinted to the left into the trees to avoid getting caught. The second skier was 30 higher on the slope. He attempted to run off the slope but was unable to avoid getting captured. He was carried to the bottom of the avalanche path, got submerged in the snow, but thankfully came to rest on the surface. His partner initiated a beacon search and called his name, quickly finding him on top of the avalanche debris. The skier sustained significant injuries. They called 911 and Gallatin Country Sheriff Search and Rescue initiated a response with the Helicopter team. The two skiers worked to address injuries while awaiting rescue. GCSAR inserted a team with a helicopter that provided medical treatment and both the injured and uninjured skiers. The GNFAC was on scene to evaluate the scene for hazards to the rescue team. 

Photo from 03/19/2024. This avalanche likely happened yesterday or earlier. 

From obs: "Toured up Mt. Rae in the boulder river drainage. Surprised to still find cold snow in spots and some still being blown around. Had some collapses and shooting cracks on the ascent. Shallow and suspicious snow for sure but a beautiful day out. "

From IG:

Southeast aspect on Mt Blackmore. Unknown time and date. Elevation 9700 to 9800’

From obs on 03/23/2024: "Debris field from likely a wet slide on a steeper slope in the back bowl near Emigrant peak. Slide was on an east-south/east facing slope. Not sure the date of slide. " 

From Obs: “We were skinning in the valley to the East of Woody Ridge near the North end and observed a wet slide occur naturally due to a point release, moving about 500 ft downslope. While that was occurring it remotely triggered a dry slab avalanche approx. 50-100 ft adjacent on the same slope and elevation. The crown appeared to be 3 ft deep, possibly thicker, but we were viewing from afar so hard to tell. 9500 ft elevation, East aspect. 12:02 PM March 17, 2024. Air temp approx. 30F clear skies all day.”

There were two loose, wet snow avalanches that we saw that had a bit of volume to them today. One on the south side of Crown Butte and the other on the southwest side of Scotch Bonnet

From Obs: "Had a pretty interesting collapse this afternoon while touring up the east ridge of Beehive. The slope I was on I measured at 30° at the highest, was below treeline but in a small meadow. The surface had melted and refroze. As I was touring across the small slope stomping to the to break the surface to set a better skin track the whole piece broke (150' wide by 50' down) together and moved down slope about 6". I quickly dug a little bit where it broke from the rest of the slope and it seamed to break near the ground, ~ 50cm and with the naked eye I could see large depth hoar crystals and little to no rounding.

While I do think it was simply a collapse I was very surprised this happened and the way this whole piece moved on such a low angle slope. I hadn't seen something like this before. Guess it lines up with just how weird this season has been. 

~8560' west facing"

We rode from Taylor Fork through Cabin Creek on March 17. We saw a few recent slab avalanches that happened after the last snowfall,...

On March 17 we saw a recent cornice fall in Sage Basin.

On March 17 we saw some recent natural wet loose avalanches in Cabin Creek

We saw a few natural wet loose avalanches run throughout the middle of the day in sunny, steep rocky terrain.

From obs 3/16/24: "Avalanche broke about 400ft wide and slid for 250 ft. 4-2ft deep at the crown. Photo shows How my sled ended up after being dragged 200ft. I was able jump off and grab a tree."

From obs: "On the morning on 3/14/24, a skier remotely triggered the Lawn Mower and an adjacent path on "Town Hill" in the Absaroka Range (outside of the GNFAC advisory area) while ascending on the other side of the ridgeline from the paths. The slide ran at least 1000 ft vertical."

From IG: "1/4 to 1/2 mile wide crown. Lawnmower and adjacent gully. 2-4 ft deep. Remote trigger from ~200 ft away. Crown is 8800 ft N/NW"

Large avalanche North face Mt Blackmore. Appeared to be potentially triggered by cornice fall from above. Crown propagated across majority of the bowl and was quite large in places. 

From Obs: "Cornice fall triggered a big one. Looks to be real fresh. last night or this morning    Broke across the whole bowl and up to 8 feet deep maybe more right in the middle. Broken trees in the debris, And ran out of sight."

On 3/10/24 Low on Daisy Road along the steep creek walls we saw three recent 2' deep avalanches. each 70-100' wide. HS-R4-D2-O. One looked within the last day or two and the other two were maybe 3-4 days old. Triggers unknown, there were various ages of sled/snowbike tracks nearby.

On 3/10/24 Between Miller and Wolverine there was a recent large avalanche that I would guess was triggered yesterday. 3-6' deep, 250-300' wide. HS-R4-D2.5-O. Video and photos attached.

A natural avalanche was witnessed on the north side of Republic Mtn. on 3/9 at 4:54pm. It appeared to break around 3 feet deep.

From obs on 03/09/2024: "Natural avalanche in Beehive Basin. On eastern aspect. (the same aspect as yesterday's "intentional cornice drop avalanche", 3/10th of a mile north) guessing the elevation is around 9,900-9,650ft." The exact date of when this avalanche is unknown. 

From obs: "Skied into Frazier basin today. Saw multiple wet loose slides on the SE face across the basin. Winds were stripping many ridge lines and loading N aspects. No avalanches related to wind loading were observed. Pit at the bottom of the basin on a SE aspect around 8200 feet had HS 185 and showed Ectx."

From IG 3/9/24: "Currently on the throne. Things warmed up quickly this morning. Wet loose, east aspect, 8500’, 10:30"

On 3/9/24 there was a big avalanche on the northeast side of Sheep that was previously not reported. It was there this morning so maybe happened yesterday. 6-8'+ deep, 500' wide R4-D3-O. Maybe/probably rider triggered from below.

Snowmobilers reported witnessing another rider trigger this avalanche and get partially buried.

Skiers on 03/10/2024 observed a natural avalanche that happened on the Naya Nuki headwall.

From 03/08/2024: On my drive to Cooke City I saw old slab avalanches in YNP near Mammoth and on Abiathar and Ampitheater among other places. These appeared to have happened earlier in the week. I also saw a more fresh looking persistent slab avalanche on Barronette, 2-3' deep and as wide as its terrain feature, 100-200' (photo).

We saw one small but deep slab on the north side of Scotch Bonnet, 6' deep x 30' wide, R1-D1.5.

We saw a fresh huge avalanche on the south side of Scotch Bonnet that happened today, 03/08, or late yesterday. 4-6' deep and 300' wide. R4-D3-O. 

Riders near lulu pass saw a recent avalache in the Rasta Chutes. 

Skiers triggered this avalanche in Beehive Basin after dropping a section of cornice onto the slope. This avalanche broke 500' wide and ranged in depth from 18 inches to 6 feet. The cornice was dropped on the shallowest portion of the crown, 18". 

There were two skier-triggered avalanches on Saddle Peak today. The first was relatively small, estimated depth of less than a foot. The second occurred later in the day and was much more significant. 

Downhill winds transported snow all day, loading wind-drifted snow onto slopes at upper and mid-elevations. At 1 PM, a solo skier descended Quarter Saddle toward Spencer's and Going Home Chute. The skier released a wind-slab avalanche that broke about a foot deep approximately 300 feet above the large cliff band on Saddle. The first release triggered a secondary slab that broke more widely (estimated 200' wide) and deeper (1-3 feet deep). The avalanche ran over the large cliffs into Going Home Chute. Bridger Bowl Ski Patrol interviewed the skier who triggered the avalanche along with a representative from GCSAR and the GNFAC. Based on the interview, the group believed it was unlikely that additional skiers were involved. Because of the interview, concerns about scene safety, and the timing of the avalanche, no search was performed on the ground. The team used binoculars from within the boundary of the ski area to look for obvious indications of a burial.

Downhill winds were drifting a good bit of snow at lower elevations. We mostly found stripped slopes and wind effect, but did find a few deeper drifts. There was a small and thin avalanche low on the east face that looks to have pulled out with this downhill wind loading. Approximately 25 ft x 25 ft vertical and ~6" deep. 

From obs on 03/09/2024: "First was in Woody Creek, right by the waterfall. D2, crown was up to 5 feet deep. NE facing 

The other was on the backside of High Hayden, in Pilot Creek. This one ran probably 1000 feet. SE facing "

Avalanches were observed on 03/09/2024 across various locations near Cooke City

Pic 1:  E aspect, 8900'.

Pic. 2:  NE aspect, 9300'

Pic. 3: SE aspect, 9000'.

Pic. 4:  E aspect, 8800'.

Pic. 5:  SE aspect, 8800'

Pic. 6:  E aspect, 9100'.

Pic. 7:  E aspect, 8800'

Pic. 8:  N aspect, 9600'

Pic. 9:  E aspect, 9100'

From IG on 3/7/24: "Buck ridge south of slatts hill, remote trigger by a snowmobile today"

From email: "This avalanche was triggered by a rider in our group on the 7th. The rider was midway up the slope, it broke above him right under the cornice and he successfully outrun the avy to the bottom. Right above the trail it looked the deepest at 10' to 12' deep at the peak and 6' plus further to the north."

From obs on 03/08/2024: "We rode out to the avalanche that was triggered yesterday on Henderson Mtn. It broke over 2000' wide (measured on GPS) and all the way up to the ridgeline, 6-10' deep and maybe 12-15' deep at the deepest section. There were a couple hundred feet of slope that had not slide between this one and the similarly large slide to the north last weekend. The deepest debris was probably 15-20"

Snowboarders in Hyalite on 03/09/2024 saw several avalanches in the upper South Cottonwood drainage. 

From obs on 03/07: "observed several crowns on Republic from Town Hill, likely from 03/06. Ray's had a slide on its west end which appeared to be isolated from the large avalanche that was filmed on the shoulder/Ray's. We saw up to 4 other crowns in Republic bowl on NE, N, and NW aspects including one that broke on the NE facing spines looker's left of the Fin that got legs and ran into the trees out of site (R1-D2?)."

From obs: "Shot from ~20 miles away, 3/8. Also looks to be a significant debris field in Frazier off The Hollywood. Bob ps. maybe a better pic"

From email: "Natural avalanches photographed near Cooke City today.

Pic 1:  east aspect 9100'.

Pic 2:  east aspect 9450'.

Pic 3:  SE aspect 10,400'.

Pic 4:  W, NW aspect 9,700'.

No collapsing nor cracking, while breaking trail and skiing today."

Toured up on the ramp yesterday. In wolverine bowl, another skier and I both popped small wind pockets (6” deep at the most) about half way done the slope on a north facing roll. We also saw lots of snow transport up high on the ridges all day, as well as some slight warming on direct south faces. 

Observation cam from IG.

On the morning of 03/06/2024 from the town of Cooke City a very large avalanche was seen on the N shoulder of republic mountain. Many other avalanches were triggered at the same time along the N face. 

From obs: "East face of Republic Mountain above Erma Mine Cabins. 8800 ft natural avalanche just below the ridge. 3-4 foot crown, Apx 100’ across, ran approximately 1000 feet down the creek bed. Appeared to be from earlier in the morning possibly when the avalanche slid off the north face of Republic, as it had a light dusting of snow over the debris. This start zone was just over the ridge from the North facing 9:14 am avalanche but I don’t think the start zones were connected."

From obs: "On a tour up Middle Peak, I saw recent avalanches, with large propagation in Middle Basin and Beehive Basin."

From follow-up email on 03/08/2024: "I sent in a photo of a large avalanche in Beehive, it looked recent, and skier triggered."

From IG:

Very large natural avalanche in the Lionhead Area. Multiple other smaller naturals as well.

Pics taken 03/05/24

Observed sometime between 03/06/2024-03/13/2024: 

"Just finished a weeklong ski from west Yellowstone to bear canyon, and thought I’d chime in that I didn’t observe anything that hasn’t been reported on already. I saw lots of deep slabs breaking near the ground, primarily on the north half of the compass. But sometimes not!.... It was interesting to see that despite the lack of snow, some avalanches were running almost full track. It seems like after a week of being on the snow I would see some sort of pattern, but I feel like I ended the trip with the same amount of confidence I entered it with, and didn’t feel comfortable exposing myself to hardly anything. 
I attached a couple photos of a slide I saw toward the head end of Swam Creek. The crown was 2-5’ deep and ~2000’ wide, and it stopped within 50’ of old growth timber. "

From obs: "Today I saw evidence of Multiple N-R2-D2-I avalanches in the fairy lake zone. All three were NE facing, around 8800’. 2 slabs in Fraizer basin and one in the basin to the south. All three looked to be from 3/3-3/4 storm cycle"

From obs: "it looked like the N/NE faces in McAtee that slid just over a week ago had avalanched again, nearly to the ground.  There were slightly dirty looking debris piles mid slope and several prominant crowns just below the ridge top but it was hard to make out details through the light snow, even with binoculars."

From obs: "We were skiing out of the Cabin Creek cabin over the weekend, mostly in the low angle terrain around Skyline Ridge. Throughout the storm on Saturday and after the clouds cleared on Sunday we experienced consistent whumpfing while breaking trail. Some were larger and some were smaller, usually triggered by the person breaking trail but some of the larger ones were triggered by the second or third skier in the track."

From obs on 03/03/2024: "White touring in the History Rock area, I spotted a couple of recent slides on the NW shoulder of Mt. Blackmore. From a distance, these look like dry-loose slides on the recent snow interface around 8,500ft. on a N-NE aspect."

From obs: "Secondhand photo and story regarding two snowmobilers sidehilling the northwest aspect of Twin Peaks and triggering the slide in the photos.  They were both able to ride out of it.  This avalanche is located about 150 yards north of the Twin Peaks avalanche accident site from January 2024."

From IG on 3/3/24. Natural on Wolverine and natural between Miller and Sunset. Looked like they went today or yesterday.

From IG on 3/3/24. Natural on Wolverine and natural between Miller and Sunset. Looked like they went today or yesterday.

From obs: "Remotely triggered a large avalanche on a N aspect at 9500 ft while ascending a ridge line [in Mill Creek, Absaroka]. We estimated the slide to be D3 R3. The crown spanned roughly 1400ft +/- and ranged between roughly 1-5ft deep. They appeared to be 2 distinct layers in the crown profile, one of recent ‘storm’ snow and a lower one above old facets. This was observed from a distance. Witnessed large trees being shaken by the slide and smaller ones completely breaking. The bottom of the run out became much more planar indicating the sheer volume of debris that filled in. Extremely powerful to witness such energy and destruction. All persons in the party were in safe terrain with no intention to ski this slope at all. "

Skiers on 03/03/2024 saw several natural avalanches that happened near Maid of the Mist on Arden Peak. These avalanches likely happened between 03/01/2024 and the morning of 03/03/2024

From obs on 03/04/2024: "Continued signs of instability on a tour in Maid of the Mist Basin. A couple large collapses down low in the trees, wind slabs above tree line on variable aspects due to swirling wind up high. Large avalanche crown (10’ - 12’ in places) at the back of the basin which looked to have been trigger from cornice fall 3-4 days ago. ECTP 28 55cm off of ground on a 5cm thick layer of facets. Pit was dug on an east facing slope at 9,100 feet."

While riding near the throne we observed a large natural avalanche that happened early in the morning on 03/03/2024. This avalanche appeared to of broken deeper than just recent storm snow. 

While riding near the throne we saw a natural avalanche that broke near the ridge line. It appeared to have happened in the recent storm snow that fell overnight on 03/02/2024. 

While in the Bridger range we saw numerous loose snow avalanches on Bridger Peak, Saddle Peak, and the Throne

From obs: "Toured to the zipper for some 25° meadows and while the skiing was excellent, the stability was not. We triggered numerous thundering whumphs and got shooting cracks, the largest of which propagated at least 100' wide! See snow profile attached with test results."

On 03/08/2024 we saw widespread avalanches along Henderson Bench as well, below the steep break over in the trees, 3'+ deep breaking across multiple terrain features through thick trees, most of the bench slid, and appeared to have happened last weekend.

From obs on 03/07/2024: "Big slide below the radio tower. Kept our distance but looks like a large crown. The base up Portal is really inconsistent. Some spots it’s great and others you sink up to your chest. Had 4 instances of whompfing on fairly flat ground in the trees.  1st picture is from today and 2nd is from Sunday"

We came across 2 deep slab avalanches near the typical Bacon Rind skin track. I suspect given the amount of snow on the debris, the failed on March 2nd. It is unknown whether they were triggered remotely or failed naturally. The avalanches were as large as they could be given the terrain constraints. Slope angles ranged from 29-33 degrees. 

While riding north of Cooke City today we observed a large debris pile southern end of Sheep Mountain. SE facing at ~9700'. With poor visibility, I couldn't see a crown but much of the path had been filled in by wind and the debris was covered with fresh snow, making it at least a few days old. This slope was remotely triggered earlier this year in January by riders from the bottom of the slope. 

From a phone call with a friend: "Pretty sure we remote triggered this slide while skiing down a low angle ridge next to it. We saw it while we were ascending the uptrack and it wasnt there on our first lap."

2 Pics are from highway and are from the next day.

N-NW Facing slope at 7600ft. approx 100 cm deep. some stepped down to ground. approx 250 feet across and ran 3-400ft vertical. Large dangerous avalanche.

From a phone call with a friend: "Pretty sure we remote triggered this slide while skiing down a low angle ridge next to it. We saw it while we were ascending the uptrack and it wasnt there on our first lap."

2 Pics are from highway and are from the next day.

N-NW Facing slope at 7600ft. approx 100 cm deep. some stepped down to ground. approx 250 feet across and ran 3-400ft vertical. Large dangerous avalanche.

Riders north of Cooke City on 03/04/2024 saw a recent natural avalanche that likely happened a few days before on 03/02/2024. 

From obs on 03/04/2024: "While traveling to Big Sky from Ennis, I noticed a large avalanche on the east face of Fan Mt.

Crown appears to start at approx. the 9500' elevation with a vertical drop of at least 2000'.  Crown appears to be 200-300 yards wide"

From email on 03/03/2024: "Two big avalanches observed above the “plug” east of Cooke city. on my ride over this AM. One ran to the road, unclear if it went over it and maybe the groomer ran over the debris. Appear natural or possibly snowmo triggered? " 

From obs: "We saw one avalanche on a southeast-facing slope. At about 7,400’ on a North facing slope we experienced a valley shaking whumpf while traveling up a heavily used ski track."

From obs: "Noticed the pictured recent avalanche on an east facing aspect in the alpine of Beehive Basin. I would estimate it at a D2 size slide. It seems to have been naturally triggered by cornice fall and likely stepped down to older faceted snow deeper in the snowpack."

6" snow since Friday at 6000' in Mill Creek, very strong winds last night. Observed this large avalanche on an east face at treeline, appears to have failed on the weak snow at the base of the snowpack. Additional crowns observed in the bowls and chutes above it (these have been repeat offenders this season). 

Guides at Beartooth Powder Guides saw numerous natural avalanches near Cooke City. They noted new snow avalanches on most slopes steeper than 30 degrees. Additionally, they saw several avalanches that broke several feet deep on east, southeast, and southwest-facing terrain. 

From IG 3/2

Riders triggered a very large avalanche on the east side of Henderson Mountain while riding across a slope below. No one was caught in the avalanche and the debris pile was estimated 20' deep in spots. 

From another obs. "Watched a large avalanche come down the big Avi path on the east side of Henderson.  The avalanche covered many snowmobile tracks from that afternoon.  The crown varied and extended for 1,000 feet below the summit ridge. It was a huge volume of snow that reached Fisher Creek. The snowmobilers were lucky, as it was large enough to be buried deep."

From obs: "Multiple avalanches on Rasta Chutes on Scotch Bonnet. Did not run full path but probably 3/4 at least. Crowns were 2-4’. Debris pile by the up track to tregencic was probably 6-8’ deep."

We rode into Tepee Basin and saw two recent avalanches. One looked like it happened this morning on a treed ridgeline, 1-1.5' deep 150-200' wide.

Skiers observed a natural avalanche on an east-facing slope that broke 3-4' deep and 100' wide. This was a very recent avalanche likely happening in the last 12-24 hours. 

From obs: "Observed Deep Slab avalanche on the Shoulder of Republic Mountain today. Went to ground runout/could see dirt throughout runout." 

From obs: "Two remote triggers from about 250ft away on a slope up lulu pass. A lot new snow and everything was sliding above 30 degrees." 

Skies on 03/02/2024 observed several natural avalanches in Divide Cirque. This avalanche broke very wide connecting several paths. 

Photo from IG, slide occurred night of 3/1.

Riders in Hyalite saw an avalanche on an east-facing slope near Maid of the Mist. This likely happened between 02/29/2024- 03/01/2024.

We rode into Tepee Basin and saw two recent avalanches. this one looked like it maybe happened yesterday, on a heavily wind-loaded slope below some cornices, 2-2.5' deep and 250-300' wide.

From a phone call:

A rider saw a large avalanche in one of the bowls around the corner of Lionhead avalanched. It likely occurred on Friday, March 1. There were holes dug in the snow indicating a buried person or sled. This is the same slope that killed a 19 year old from MN on December 28, 2006. They conducted a beacon search on the debris to make sure no one was buried.

From a phone call:

A rider was traversing a slope when he triggered and was caught in a slide. He was partially buried under his sled and was uninjured. He estimated the slide to be 150 yards wide and a few feet deep and breaking to the ground.

Skiers at Mt. Blackmore on 03/01/2024 saw numerous loose snow avalanches. 

Riders on 03/01/2024 saw 2 fresh natural avalanches below the saddle between Naya Nuki and Sacajewea. 

Riders on 03/01/2024 noticed several loose snow avalanches on steep terrain below Hardscrabble Peak.   

From obs: "While touring in the Bacon Rind area today, our group experienced three audible collapses, one of which was extremely large and thundering. All of these collapses were experienced in the flat meadow areas below the typically skied slopes. "

From obs on 03/01/2024: "Looking out towards Divide Peak and the Divide Cirque at the end of the day, we noted 3 fresh crowns that were not present in the morning. These were D1 to D1.5 in size, breaking along the base of cliffs, and appeared to be wind slab avalanches from a brief peek through some glass. There was a lot of small loose dry activity that we observed across canyon at middle to upper elevations as you would expect with strong winds and fresh snow. All activity was in line with what one would expect given the forecast and weather inputs. "

Skiers on 02/28/2024 experienced widespread collapsing while in the Mosier Creek drainage in Hyalite. 

From obs on 02/29/2024: "observed 2 crowns in wind loaded terrain. One at the end of Woody ridge on a north facing sub ridge (Peterson’s prow ) and the other on an East facing Ridge seen from the top of Wyoming bowl. "

Skiing some dog pow across Hyalite reservoir between 7200-7800’ on a NE pitch I got lots of whumphs and shooting cracks while braking trail. This was a shallower snowpack than most other areas, it was still easy to break into basil facets with skis on.

From obs: "I was skiing inbound at Bridger Bowl today and noticed a small wind slab avalanche that failed on quarter saddle. I estimate comparing the photo to Google Earth that the slide ran 250 vertical feet and broke 100+ feet wide. Ongoing wind-loading and obvious instability. "

From IG: This avalanche was from this morning (02/28). It was windy and the gully was likely wind-loaded. One video shows the debris and crown. The pin on the map (below) shows the location of the debris.

On 02/29/2024: From the parking lot near Hebgin Lake, we were able to see several natural avalanches that happened on Lionhead Ridge. These avalanches all occurred in a similar timeframe to each other. While riding below Lionhead Ridge we observed another avalanche that likely happened a few days prior near 02/27/2024. 

We noted a relatively small storm slab avalanche the failed on the wall of Sage Basin. 

From email: "We didn't see any avalanches on E Henderson or E Sheep with decent vis on the ride in. One large avalanche on a heavily wind loaded slope below a huge cornice north of Scotch Bonnet. That one looked like it broke deeper/in the old snow, about 100' wide. Also saw one wind slab on a small slope north of Long Lake. 14-16" deep, 20' wide, and within the fresh wind slab. "

Riders on 02/29/2024 observed a small avalanche while riding in Portal Creek. They estimated that the avalanche likely happened before a storm that began on 02/27/2024. 

From IG message: “These are on the ridge between Miller Mtn and Sunset Peak on North aspect. All of the North facing ridge of Miller Creek up to Miller Mountain had similar slides too. The crowns filled back in overnight… The North facing ridge on Sheep Mtn slid as well, not sure on the trigger but a rider from another group send the following image of the Sheep slide“

Skiers intentionally triggered a wind-slab avalanche at the cornice near the prayer flags in Bear Basin. Strong winds have drifted snow for the last two days.

From Obs: "Toured up the west side of Woody via Central Park approach. Moderate to high wind gusts at the ridge line. Skied a couple laps in variable conditions on Sub bowl and then returned to the West aspect for a lap down South Central . 

Traversed into the tube at tree-line roughly 9900’ and triggered a small wind slab. Crown was around ~1 foot deep and maybe 40 feet wide. Possibly stepped down a bit once in the tube and then ran for about 300 feet. 

HS-AS-D1-R1"

This avalanche likely happened in the last 24 hours following a large increase in windspeed beginning early in the morning on 02/24/2024. 

From obs: "Large slide in the north basin of Fan Mountain. The flies is below the north, northeast couloir and the crown runs all the way around the basin. It went to the ground below the couloir and a few other places. 10ft crown probably at the biggest point below the couloir. "
 

A rider reported a large avalanche in Targhee Creek that likely broke on Feb 23. He estimated the slide broke 1000' wide, 3-4' deep and ran 650' vertical. 

From obs 2/24/24: "Saw multiple large slides around the McAtte drainage N/NE aspects. Some were larger than others but all ran on what looked like a persistent grain or even to the ground in some. Probably natural released over last few days."

 

On 2/24/24 We saw a slide on the north end of Sheep Mtn. on a slope above the steep chute where people climb out of Goose Creek (photos attached). This slide had not been reported previously and looked similar in age to the two triggered yesterday, so maybe broke naturally or human-triggered in last 24 hours. It broke near a scoured north facing ridgeline, 1-1.5' deep, 175' wide. HS-R3-D2-O.