Trip Planning for Cooke City Area

"Attached are a few photos of old deep slab avalanches north of town... the south face of scotch bonnet. Hard to tell the depth of the crown but it’s very visible from the lulu road, so probably pretty deep." Photo: Z. Peterson

Attached are a few photos of old deep slab avalanches north of town... a south face north of round lake above 10,000’. The crown was mostly filled in but the deepest exposed part was 2-3’ deep. Photo: Z. Peterson

From 3/18/23: "Watched two riders on the north side of Henderson / Daisy pass high marking. One triggered a large avalanche and got stuck at the crown. Crown was taller than him. Guessing 8-10’ deep and 200+ yards wide.... We were across around the sheep mtn/ Scotch Bonnet area and watched the whole thing happen. We boogied over there as fast as possible to help." Photo: C. Diffley

From 3/18/23: "Watched two riders on the north side of Henderson / Daisy pass high marking. One triggered a large avalanche and got stuck at the crown. Crown was taller than him. Guessing 8-10’ deep and 200+ yards wide.... We were across around the sheep mtn/ Scotch Bonnet area and watched the whole thing happen. We boogied over there as fast as possible to help." Photo: C. Diffley

A few recent slides were visible today on south, east and west aspect around goose lake zone. Looked like mostly wind slabs in the new snow. Photo: P. Hinmon

A few recent slides were visible today on south, east and west aspect around goose lake zone. Looked like mostly wind slabs in the new snow. Photo: P. Hinmon

Saw this natural D2 soft slab off the east aspect of Miller Ridge. The crown looks shallow, so I’m guessing it ran at the storm interface. 3/16/23. Photo: N. Hance

From Obs: "Heard tree breakage, saw plumes of snow and sliding snow at the bottom of the slide path. Our group spoke with the sledders and skiers that were on the slope and confirmed none were caught. Skiers reported feeling slide tremble and backed down the mountain. The main breakage was near top of the third shoot from the lookers right." Photo: N. Repphun

From obs: "I triggered an avalanche on the way back down the mountain. I'm unsure of the exact location but a buddy said it was under bear tooth butte. I was able to outrun the avalanche, and there were no injuries."

From obs: "I triggered an avalanche on the way back down the mountain. I'm unsure of the exact location but a buddy said it was under bear tooth butte. I was able to outrun the avalanche, and there were no injuries."

From obs: "Large avalanche with small tree and branch debris. Located on the lower NE bench face of Mt Abundance, near Lake Abundance. There were snowmobile tracks near the slide but could not determine if that was the cause. Approx 2000 feet across. Possibly 4-6 feet deep but couldn't tell from the bottom of the hill." Photo: D Green

From obs: "Large avalanche with small tree and branch debris. Located on the lower NE bench face of Mt Abundance, near Lake Abundance. There were snowmobile tracks near the slide but could not determine if that was the cause. Approx 2000 feet across. Possibly 4-6 feet deep but couldn't tell from the bottom of the hill." Photo: D Green

Snowmobile triggered on a path called "Marty's" above Daisy Pass road. This was similar aspect as the slide on Crown Butte yesterday, and likely had a similar snowpack structure. We checked the debris for a beacon signal to be sure no one was caught, and did not find one. This may have been triggered today (3/12). Photo: GNFAC

Snowmobile triggered on a path called "Marty's" above Daisy Pass road. This was similar aspect as the slide on Crown Butte yesterday, and likely had a similar snowpack structure. We checked the debris for a beacon signal to be sure no one was caught, and did not find one. This may have been triggered today (3/12). Photo: GNFAC

Snowmobile triggered on a path called "Marty's" above Daisy Pass road. This was similar aspect as the slide on Crown Butte yesterday, and likely had a similar snowpack structure. We checked the debris for a beacon signal to be sure no one was caught, and did not find one. This may have been triggered today (3/12). Photo: GNFAC

Slide on Crown Butte that was triggered by a snowmobiler yesterday (3/11/23). This was on a SW aspect at 9,600'. It was 1-3 feet deep and broke on a layer of surface hoar and large facets below a hard slab of wind-drifted snow. Photo: GNFAC

Natural on the east side of Sheep Mtn. that was a hard slab of wind-drifted snow on a heavily wind loaded slope near the high ridgeline at 10,500', East aspect. Photo: GNFAC

This slide on Fisher Mtn. was a very large natural that broke the night of 3/10-3/11, and appeared up to 10 feet deep. 10,200', E aspect. Photo: GNFAC

This slide on Fisher Mtn. was a very large natural that broke the night of 3/10-3/11, and appeared up to 10 feet deep. 10,200', E aspect. Photo: GNFAC

This slide on Fisher Mtn. was a very large natural that broke the night of 3/10-3/11, and appeared up to 10 feet deep. 10,200' E aspect. Photo: GNFAC

From FB message: "triggered this today (3/11/23) in Cooke City south side of Crown Butte."

Large natural avalanche on Fisher Mtn. observed 3/11/23 (screenshots from IG story, A. Mulkey)

Large natural avalanche on Fisher Mtn. observed 3/11/23 (screenshots from IG story, A. Mulkey)

From obs 3/11/23: "Saw a deep crown today in Republic Valley. This is peak 10383 (just north east of republic peak). Crown looks about 100 feet wide and probably 5 feet deep. Couldn’t see debris or how far it ran." Photo: J. Mundt

On the afternoon of 3/11/23 there was a large avalanche in the main gully on Town Hill (southerly aspect) above Cooke. Photo: GNFAC

Several avalanches observed D2-D2.5.
Crown depth 80-120cm
SSW @ 8800’

Photo: B. Hoiness

Several avalanches observed D2-D2.5.
Crown depth 80-120cm
E @ 9700’
Photo: B. Hoiness

Several avalanches observed D2-D2.5.
Crown depth 80-120cm
ENE @ 10,000’
Photo: B. Hoiness

Observed 3/11/23: E aspect, around 9,000'. Photo: B. Fredlund

Seen 3/11/23, NW aspect, around 10,000'. (This starting zone also avalanched in a similar way around Feb. 21). Photo: B. Fredlund

Photo attached of a recent avalanche near Cooke, on the north face of Mt. Republic.  Steep, rocky, north facing.  Everything that I have been seeing the last 2 days has been similar:  steep, rocky north faces above tree line, often associated with wind loading, and cornices.  We observed 4 other similar avalanches yesterday, like the photo attached.

A group of snowmobilers captured an image of what we believe was a skier-triggered avalanche on Miller Mountain from 3/2. Photo: R. Stacy

From obs. "Around 4 or 5 pm today we rode out of Sheep Creek into the Miller Mountain area. When we looked at Miller there was a large avalanche that appeared to have occurred naturally (to our knowledge). It looked like the crown was 12-24'' and a few hundred feet wide. The debris looked fresh and must have occurred today. Given the depth we assumed it was windslab that had built up sometime in the last few days; however, hard to tell from so far away." Photo: R. Stacy

From obs. "Around 4 or 5 pm today we rode out of Sheep Creek into the Miller Mountain area. When we looked at Miller there was a large avalanche that appeared to have occurred naturally (to our knowledge). It looked like the crown was 12-24'' and a few hundred feet wide. The debris looked fresh and must have occurred today. Given the depth we assumed it was windslab that had built up sometime in the last few days; however, hard to tell from so far away." Photo: R. Stacy

On Buck Ridge today (3/5/23) we found fresh, unstable drifts. This fresh slab was 4-6" deep. Cracking like this is a sign that wind slabs will avalanche on steeper slopes. Photo: GNFAC

Walking along Henderson ridge, Doug Chabot touched a cornice with his ski pole and it broke 40 feet wide. Cornices are touchy and need t be given a wide berth. Photo: GNFAC

The slope angle at the crown was shallow: 31-32 degrees. A weak layer of surface hoar is notorious for breaking on shallow-angled slopes. Photo: GNFAC

From 3/3/23: "Here is a picture of an avalanche that occurred between Daisy and lulu road just off HWY 212 today. SE facing slope that was snowmobile triggered" Photo: B. Zavora

Triggered by skiers on 3/2/23. "....Crown looks 5-6' deep, 150'+ wide and SW aspect." Photo: B. Zavora

Skier triggered avalanche near Daisy Pass that was triggered the afternoon of 3/2/23. Photo: R. Stacy