Trip Planning for Lionhead Range

as of 5:00 am
Today0″ | 25-34 W
Feb 22 0″ | 10-20 W
Feb 21 0″ | 10-20 W
9420′     02/23 at 15:00
18.8℉
W - 25mph
Gusts 36 mph
7750′     02/23 at 15:00
30℉
60″ Depth
Primary Problem: Persistent Slab
Bottom Line: A person can trigger large avalanches that break on weak layers buried 1-3 feet deep. These persistent slab avalanches can break hundreds of feet wide, and can be tricky as they might be triggered by the first rider, or after multiple people have ridden a slope. Be cautious of slopes steeper than 30 degrees, particularly at middle and lower elevations. Watch for fresh drifts that grow from today’s winds and old drifts that haven’t bonded yet.

Past 5 Days

Wed Feb 19

Considerable
Thu Feb 20

Considerable
Fri Feb 21

Considerable
Sat Feb 22

Considerable
Today

Moderate

Relevant Avalanche Activity

Lionhead Range
Lionhead Ridge
Remotely Triggered Avalanche Lionhead
Incident details contain video
Lionhead Ridge
SS-AMr-R3-D2-O
Elevation: 8,600
Aspect: SE
Coordinates: 44.7145, -111.3180
Caught: 0 ; Buried: 0

As we approached our second pit site on the lip of Moto Hill (southeast aspect at 8600'), I stopped and looked back in time to see avalanche debris slamming into the trees on a connected slope below. We remotely triggered the avalanche from 150 feet away. It broke 200' wide and 1-3 feet deep. It ran an estimated 200' vertical feet (based on a slope map. We couldn't safely access the toe of the debris). The avalanche failed on a layer of Fist hard facets. This is interesting because it is these mid-elevation slopes in the LH area that seemed really weak on previous visits to the area. The slope may have some wind-loading, but it was minimal and not the cause of this avalanche. 

We dug a pit on an east aspect around the corner and down from Airplane Bowl (before the avalanche) and found a similar snowpack setup. 150 cm of total snow and half was composed of weak facets. ECTP22 and P24 on the mid-pack January layer of Fist hard facets and surface hoar

Take Homes: 

  1. Lionhead seems to be the epicenter of persistent slab instability. It is the weakest I have seen. Southern Madison and Southern Gallatin seem to be similar and I would group them together when describing conditions. 
  2. Mid-elevation slopes are thin and weak and can clearly avalanche. This is problematic because many folks play in lower elevation terrain when conditions are dangerous... While small compared to the upper bowl, the avalanche we triggered would have been deadly. It was deep and it would have strained its victim through trees. 
  3. We heard about a similar remote-triggered avalanche in Black Canyon today. This has me nervous that I missed something in the Centennials. While we didn't see anything too concerning there yesterday outside of wind-loaded slope, I am not happy about two remotely triggered slides less than 20 mile away. 

More Avalanche Details
Out of Advisory Area
Black Canyon
Remotely Triggered Avalanche in Black Canyon
Incident details include images
Black Canyon
SS-AMr-R3-D2-O
Elevation: 8,000
Coordinates: 44.4780, -111.1350
Caught: 0 ; Buried: 0

From SnoWest Forums FB Page:

“Just getting word of a LARGE Remote Rider Triggered Slab Avalanche down inside of Black Canyon itself just off the Black Canyon Loop Trail in Island Park.
A 3-4ft thick slab broke loose and filled the bottom of the canyon with 12-15 FEET of debris, completely blocking off the canyon itself. Rider was NOT caught in it!! Had the rider been caught, there would have been ZERO chance of rescue under such a deep slide!”


More Avalanche Details
Lionhead Range
LIONHEAD AREA
Wind Slab/Persistent Slab Avalanche in Lionhead
LIONHEAD AREA
AM
Coordinates: 44.7254, -111.3320
Caught: 0 ; Buried: 0

Avalanche in Lionhead. Broke on wind slab then triggered persistent slab underneath.


More Avalanche Details

Relevant Photos

Displaying 1 - 40
  • At Lionhead a weak layer generally 2-3 feet deep is obvious in this snowpit wall.

  • Remotely triggered the avalanche from 150 feet away. It broke 200' wide and 1-3 feet deep. It ran an estimated 200' vertical feet 

  • Remotely triggered the avalanche from 150 feet away. It broke 200' wide and 1-3 feet deep. It ran an estimated 200' vertical feet 

  • From FB message: "Small slide in lower elevation back by lionshead"

  • From obs: "We saw this today after it happened. Looked like a snowmobile triggered it. I believe it is mostly south facing." Photo: D. Haluptzok 

  • We saw two recent shallow wind slab avalanches. No recent slides breaking deeper. 
    This one at NE 9000'

  • Plenty of wind slabs ranging in size on Lionhead ridge and on surrounding slopes. Photo: Riley

  • Plenty of wind slabs ranging in size on Lionhead ridge and on surrounding slopes. Photo: Riley

  • Plenty of wind slabs ranging in size on Lionhead ridge and on surrounding slopes. Photo: Riley

  • 1 meter deep snowpack showing the obvious facets in the bottom third

  • We dug a pit on an East facing aspect below the slope we had planned to ride. The height of snow was about 110 cm and there was a very concerning layer of large facets at 75cm deep going to the ground.  Photo: C Culver

  • Our results were CT17 SPQ2 and ECTP26 SCQ1. Bother failures during tests were on the layer of facets and on the CT and ECT our columns easily separated from the facet layer after failure. Photo: C Culver 

  • On Jan 12, we saw 4-5 avalanche crowns that were up to a week old, some had been reported and a few we had not heard of. Two were ~2' deep on less wind affected slopes lower down in the trees, but probably had some previous wind-loading. Photo: GNFAC

  • On Jan 12, we saw 4-5 avalanche crowns that were up to a week old, some had been reported and a few we had not heard of. Two were ~2' deep on less wind affected slopes lower down in the trees, but probably had some previous wind-loading. Photo: GNFAC

  • On Jan 12 We saw 4-5 avalanche crowns that were up to a week old, some had been reported and a few we had not heard of. The pictured one was a 3-4'+thick slab on a rocky heavily wind-loaded slope off Lionhead ridge. Photo: GNFAC

  • From IG Jan4, Photo: J. Urell

  • From IG Message Jan 4."They happened today because I did not see the debris on way in". Photo: T. Urell

  • Remote triggered this avalanche at Lionhead. We were snowmobiling to the left of where the avalanche occurred. No one was caught.

    Coordinates: 44°43'36.8"N 111°19'05.0"W

    Photo: Ben 

  • Settling and collapsing on E-NE slopes above Hebgen. Full slope collapses and cracks, approximately 28 degree slope pictured.

    Photo: C Koch

  • While touring up a low-angle ridge in the northern Lionhead, I experienced several large collapses, notably one that triggered a cornice fall from 50’ away. Another remote collapse caused about 500’ of an E facing bowl to propagate, but not slide. ~9200’ E-SE 

    Photo: N Sramek

  • While touring up a low-angle ridge in the northern Lionhead, I experienced several large collapses, notably one that triggered a cornice fall from 50’ away. Another remote collapse caused about 500’ of an E facing bowl to propagate, but not slide. ~9200’ E-SE

    Photo: N Sramek

  • There was a natural avalanche on the landslide face above quake lake. The avalanche failed on a weak layers near the ground and broke several hundred feet wide. 

  • From obs on 12/29: "On our way out near the cabin I cut a line close to a creek to see if I could trigger something."

  • From obs on 12/29: "On our way out near the cabin I cut a line close to a creek to see if I could trigger something."

  • Occurred during the day on 12/28 Photo: GNFAC

  • Plumes of drifting snow in the Bridger Range as strong winds blasted the mountains. Photo: GNFAC

  • From IG: On 12/15 "Storm slab broke about 200’ above us as skinning up the hallway coming from the north side on the throne." Photo: Anonymous

  • Gusty winds transporting snow in Taylor Fork on Saturday. Triggered a 4-5 inch deep wind slab that propagated about 50 ft at the top of a north east facing slope at 9,500 ft.

    Photo: JP

  • WE facing snow at 8100 ft Cabin Ck

  • Cabin Creek snow cover

  • SE facing snow Cabin Creek

  • N facing snow Cabin Creek, 9000 ft

  • Big Sky Ski Patrol triggered this avalanche during mitigation work in The Wave on 11/26/24... "2-3' deep on an ice crust just above the ground with a 2# shot in the Upper rodeo. Volume was limited as most of the snow was loaded just underneath the cornice, but still produced a sizeable size 2... Other paths in the Lenin region ran meaty wind slabs, full track with no significant step downs." Photo: BSSP

  • Cracking on old, faceted, October snow hundreds of feet long. North facing near treeline. Photo: BSSP

  • Intentional, human-triggered avalanche by a ski patrol breaking at the ground on a north facing slope near treeline. Photo: BSSP

  • Snowpack on Ski Hill at Lionhead. Photo: GNFAC

     

  • Snowpit at Bridger Bowl on 11/5. Photo: B. VandenBos

  • From e-mail: "Photo attached from near top of hyalite peak, 11/2. Cracking in recent hard wind slab, I had to really jump hard to make this. Walked on many other hard slabs that were well bonded. Highly variable snowpack. I think you'd be most likely to get into trouble by popping out a small hard slab pocket like this and getting magic carpeted into some thinly covered terrain." Photo: B. VandenBos

WebCams


Rendezvous Ski Trail, W. Yellowstone

Snowpit Profiles- Lionhead Range

 

Select a snowpit on the map to view the profile image

Weather Forecast Lionhead Range

Extended Forecast for

10 Miles WNW West Yellowstone MT

  • This Afternoon

    This Afternoon: A 40 percent chance of snow.  Cloudy, with a high near 25. Southwest wind around 20 mph, with gusts as high as 29 mph.  Total daytime snow accumulation of 2 to 4 inches possible.

    High: 25 °F

    Chance Snow

  • Tonight

    Tonight: Snow, mainly before 5am.  Low around 23. Breezy, with a southwest wind 20 to 23 mph, with gusts as high as 30 mph.  Chance of precipitation is 90%. New snow accumulation of 1 to 3 inches possible.

    Low: 23 °F

    Snow and
    Breezy

  • Monday

    Monday: A 40 percent chance of snow, mainly after 1pm.  Mostly cloudy, with a high near 30. Southwest wind 18 to 20 mph, with gusts as high as 29 mph.  New snow accumulation of less than a half inch possible.

    High: 30 °F

    Mostly Cloudy
    then Chance
    Snow

  • Monday Night

    Monday Night: Snow, mainly after 10pm.  Low around 21. Breezy, with a south southwest wind 22 to 25 mph, with gusts as high as 33 mph.  Chance of precipitation is 80%. New snow accumulation of less than one inch possible.

    Low: 21 °F

    Snow and
    Breezy

  • Tuesday

    Tuesday: Snow.  High near 24. Breezy, with a west southwest wind 20 to 22 mph, with gusts as high as 30 mph.  Chance of precipitation is 80%. New snow accumulation of less than one inch possible.

    High: 24 °F

    Snow and
    Breezy

  • Tuesday Night

    Tuesday Night: A 50 percent chance of snow before 11pm.  Mostly cloudy, with a low around 14. West southwest wind 10 to 20 mph, with gusts as high as 26 mph.  New snow accumulation of less than a half inch possible.

    Low: 14 °F

    Chance Snow
    then Mostly
    Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 27. Southwest wind 8 to 13 mph.

    High: 27 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 12. South southeast wind 10 to 14 mph, with gusts as high as 18 mph.

    Low: 12 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 32.

    High: 32 °F

    Mostly Sunny

The Last Word

02 / 22 / 25  <<  
 
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