Trip Planning for Lionhead Range

As we rode into Lionhead we saw many slides that either ran naturally or from cornice falls. Most of the slides happened Fri or Sat. Winds are blowing strong at all aspects and elevations. Slopes are being loaded further and we triggered a small slide (video) from 50 feet away (aka remotely triggered). This is a serious sign of instability and we were careful to not get on or underneath avalanche terrain.

As we rode into Lionhead we saw many slides that either ran naturally or from cornice falls. Most of the slides happened Fri or Sat. Winds are blowing strong at all aspects and elevations. Slopes are being loaded further and we triggered a small slide (video) from 50 feet away (aka remotely triggered). This is a serious sign of instability and we were careful to not get on or underneath avalanche terrain.

As we rode into Lionhead we saw many slides that either ran naturally or from cornice falls. Most of the slides happened Fri or Sat. Winds are blowing strong at all aspects and elevations. Slopes are being loaded further and we triggered a small slide (video) from 50 feet away (aka remotely triggered). This is a serious sign of instability and we were careful to not get on or underneath avalanche terrain.

Observed two recent natural avalanches on 1/25/23 that broke 1-2 feet deep, presumably on a surface hoar layer. There was a couple of inches of snow on each of these slides, so I would place them between three and five days old. The slides were R1-D1.5 in size - 75-100' wide, 1-2' deep, and 100' vertical fall. Photo: GNFAC

Observed two recent natural avalanches on 1/25/23 that broke 1-2 feet deep, presumably on a surface hoar layer. There was a couple of inches of snow on each of these slides, so I would place them between three and five days old. The slides were R1-D1.5 in size - 75-100' wide, 1-2' deep, and 100' vertical fall. Photo: GNFAC

Surface hoar can often be seen as a grey stripe on the wall of your snowpit as was the case at Bacon Rind in the Southern Madison Range on 1/23. Photo: GNFAC

A natural slide in the back bowls of Lionhead.

Dave and Doug rode around and saw multiple natural and 1 sledder triggered slide on Lionhead. Some were thin and just involved news snow and others were deeper and broke on the buried surface hoar layer.

Dave and Doug rode around and saw multiple natural and 1 sledder triggered slide on Lionhead. Some were thin and just involved news snow and others were deeper and broke on the buried surface hoar layer.

Small avalanche broke while descending to less exposed areas.  Approximately 80 yards wide, 18” deep.  Slid for approximately 90 yards from crown. 
 

Small avalanche broke while descending to less exposed areas.  Approximately 80 yards wide, 18” deep.  Slid for approximately 90 yards from crown. 

Small avalanche broke while descending to less exposed areas.  Approximately 80 yards wide, 18” deep.  Slid for approximately 90 yards from crown. 
 

On a Jan. 16 tour into Beehive, we found the concerning layer of feathery surface hoar buried under 6" of snow. It is widespread from Big Sky through West Yellowstone and Cooke City. It has produced avalanches near Hebgen Lake, with more snow, it will likely produce avalanches in Beehive too. Photo: GNFAC

Skinned up to the ridge and when we were almost to the top my partner was out front and triggered a noticeable whumpf.    ESE aspect, 8950 ft.

HS = 135

SH at 105 cm, ECTP3

DH at 45 cm, ECTP23

Skier unintentionally triggered and was caught in wind slab avalanche on the Y couloir in Sheep Creek Drainage. Skier was carried 10m before self arresting. The slide ran ~250m down and broke across the entire width of the couloir. There were no injuries and skied away. 

The snow rangers from the Hebgen Lake Distract standing on the debris of a large avalanche near the Airplane Bowl at Lionhead Area. Photo: GNFAC

We observed several recent storm and wind slab avalanches from Lionhead Ridge. Photo: GNFAC

We observed several recent storm and wind slab avalanches from Lionhead Ridge. Photo: GNFAC

We looked at the avalanche that killed a snowmobiler yesterday (12/31/22) on Crown Butte near Cooke City. Our deepest condolences go out to the family and friends of the victim, and those involved with the rescue and recovery. Photo: GNFAC

On the way back to Lionhead.  Came upon this recent avalanche.  Rushed up to the group of 4 guys.  They were fine, not the guys who set it off.  The group of 6 we passed going there set it off.  The group of 4 said they saw these guys ... all on the hill at same time, stuck and climbing around the stuck guy.  All were okay but I hear one guy was shaken up. 4-5ft deep at break by 200-300ft wide, ran 400+ft. Photo: T. Anafarta

On the way back to Lionhead.  Came upon this recent avalanche.  Rushed up to the group of 4 guys.  They were fine, not the guys who set it off.  The group of 6 we passed going there set it off.  The group of 4 said they saw these guys ... all on the hill at same time, stuck and climbing around the stuck guy.  All were okay but I hear one guy was shaken up. 4-5ft deep at break by 200-300ft wide, ran 400+ft. Photo: T. Anafarta

On December 31, 2022 a snowmobiler was killed in a very large avalanche north of Cooke City, MT. The avalanche occurred near Daisy Pass on Crown Butte on a southeast facing slope at 9,800’. The avalanche appeared to be 2-4' deep, 500' wide, 600' vertical, and broke on weak snow near the bottom of the snowpack. Photo: GNFAC

Many slick roofs shed this winter's snow with the above-freezing temperatures. There are some impressive fracture lines at the ice rink in Bogert Park in Bozeman. Photo: GNFAC

Alex Marienthal cuts a column for his stability test on Ski Hill in Lionhead. Photo: GNFAC

Alex Marienthal points a 5 cm thick weak layer of faceted snow that broke with an ECTP10. Photo: GNFAC

This Beacon Checker was installed by the Hebgen District FS snow rangers at the trailhead to Denny Creek and Lionhead Ridge. It was made possible by the family of Bradie Becker in partnership with The Friends of GNFAC. Bradie was killed in an avalanche on Lionhead Ridge on February 6th, 2022. Photo: J. Norlander

We dug a pit at 9,000 feet on a SE facing slope above Hebgen Lake. We found weak snow under a slab that broke with an ECTP26. Photo: GNFAC

Participants in the West Yellowstone Avalanche Fundamentals Field Session found unstable conditions near "Ski Hill" in the Lionhead area on December 6, indicating that large, human-triggered avalanches are possible. Photo: GNFAC

From IG 12/3: "It was natural. Happened last night or this morning. It hadn't slid when we left yesterday. We were first tracks in today, and there were no tracks above or below this slide. Crown at the peak was around 6'. Average 2-3' crown. 10' debris piles at least." Photo: R. Malmstrom

From IG 12/3: "It was natural. Happened last night or this morning. It hadn't slid when we left yesterday. We were first tracks in today, and there were no tracks above or below this slide. Crown at the peak was around 6'. Average 2-3' crown. 10' debris piles at least." Photo: R. Malmstrom

Photo: R. Malmstrom

Lots of avalanche activity. Lots of cracking and propagation from the skis. Photo: R. Malmstrom

Lots of avalanche activity. Lots of cracking and propagation from the skis. Photo: R. Malmstrom

Lots of avalanche activity. Lots of cracking and propagation from the skis. Photo: R. Malmstrom

Lots of avalanche activity. Lots of cracking and propagation from the skis. Photo: R. Malmstrom

Lots of avalanche activity. Lots of cracking and propagation from the skis. Photo: R. Malmstrom

A snowmobiler noted cracking of the snow surface on the south face of Reas Peak out of Island Park. The wind crust was 3-4" thick and had facets underneath which aided the propagation. Photo: Anonymous

Big Sky ski patrol triggered these slides with explosives on 11/22 during routine avalanche mitigation work. The avalanches were hard slabs that averaged 12" deep and broke on a weak layer above a crust on top of snow that fell in October. Photo: BSSP

Big Sky ski patrol triggered these slides with explosives on 11/22 during routine avalanche mitigation work. The avalanches were hard slabs that averaged 12" deep and broke on a weak layer above a crust on top of snow that fell in October. Photo: BSSP

Observer reported "A number of Avalanche Crowns on an east aspect at 9500 ft." in Tepee Basin.