Trip Planning for Centennial Range

as of 5:00 am
Feb 110″ | 15-40 W
Feb 10 0″ | 10-30 W
Feb 9 0″ | 10-30 W
8775′  04/03 at 10:08
23℉
SW - 7mph
Gusts 10mph
7750′   05/15 at 22:00
48℉
42″ Depth
Bottom Line:

Snow Observations- Island Park & Lionhead

Island Park
Yale Creek
Hotel/Yale Creek
Incident details include images

Wednesday we were on snowbikes in the Hotel/Yale Creek drainages. We beat the snow up pretty hard on steep short slopes with no signs of instability. There was approximately 1" to 1.5" of new snow within the last week that could have easily been surface frost, frozen fog or just light snow. The weather was mild with clear skies to partly cloudy skies and a minimal amount of new snow falling. There is about 3 layers in the snow pack, the surface was light for the top 1/3, getting ice and crusty on the south slopes. We could hear the ice on the skies. The middle third of the snow pack is pretty consolidated, and the bottom snow pack with the temperature variance with the last weeks of high pressure systems seems to be falling apart and faceting. What we have seen in the last couple of weeks is a pretty solid base, however, with the longer high pressure systems, it appears to be coming apart down low towards the ground. We have seen this in many places in Eastern Idaho lately. Many of the streams are open in the big drainages due to the lack of snow. Places to cross can be challenging. 

Full Snow Observation Report
Island Park
Tin Cup Pass
Good stability outside Island Park
Incident details include images

From the Gallatin NF Avalanche Center:

We rode up Yale Creek, then to the Mt. Jefferson Bowl, then to Tin Cup Pass north of Mt Raes. We  saw no avalanche activity or signs of instability. It was calm out and the wind was not moving snow. The debris piles on Mt. Jefferson were from an avalanche cycle the end of December and they are still visible. January has been dry! 

Our stability test did not break on the surface hoar . There needs to be more snow on top of it. Possibly on a wind drifted area, but in general, the stability is good until we get more snow. 

Full Snow Observation Report

Relevant Avalanche Activity

Lionhead Range
Ski Hill
Fatal Avalanche Ski Hill
Incident details include images
Incident details contain video
Ski Hill
SS-AMu-R1-D2-O
Elevation: 8,100
Aspect: E
Coordinates: 44.7016, -111.2930
Caught: 1 ; Buried: 1; Killed: 1

On Sunday, one snowmobiler in a group of four was caught and killed in a small avalanche on Ski Hill at the south end of Lionhead Ridge. He was on a 45-degree slope when it released and partially buried him against a tree. The slide was only 4"-11" deep, 75 feet wide and ran 300 feet vertical. His head was a foot under the snow. The avalanche was not witnessed and the victim was buried an estimated 15-25 minutes before he was uncovered. Rescue efforts were not successful. The group was familiar with the area and had rescue gear. The shallow, steep slide ended in trees, a terrain trap . Our deepest condolences go out to the family and friends of the rider. 

A detailed report can be read here.

 


More Avalanche Details
Cooke City
Goose Lake
Partial Burial on Sawtooth Mountain near Goose Lake
Incident details include images
Goose Lake
SS-ASu-R2-D2-O
Elevation: 10,800
Aspect: SE
Coordinates: 45.1437, -109.9040
Caught: 1 ; Buried: 1; Killed: 0

This morning while ascending a line on Sawtooth Mountain (Lower Novocain) we triggered an avalanche (ASu-SS-R2-D2-O)  that caught and carried my partner an estimated 180M and partially buried him. His leg and hand were unburied and excavation of the head was done in less than 2 minutes of the incident. The avalanche only involved new snow from the last 48hrs and was triggered on a MF crust/facet combo 30cm down(formed 1/30/22). The avalanche was 30cm at its deepest and 20-30M wide and ran 250M. We were lucky to find both skis and poles a little ways downslope. No injuries were sustained.

We both agree that we were trying to outsmart the instability that was present on steeper S facing terrain and should have turned around much sooner, we were very lucky. There was 30+cm HST in favored areas and the high winds from 1/31/22 formed some sensitive windslabs in specific areas. 

 


More Avalanche Details
Lionhead Range
Lionhead Ridge
Avalanche near Lionhead Peak
Incident details include images
Lionhead Ridge
SS-N-R3-D2-O
Elevation: 9,000
Aspect: NE
Coordinates: 44.7328, -111.3320
Caught: 0 ; Buried: 0

This avalanche broke wide in a northerly facing bowl off Lionhead Ridge. It looks to have broken a foot or less deep. The propogation indicates a uniform weak layer , likely near-surface facets or surface hoar .


More Avalanche Details

Relevant Photos

Displaying 1 - 36
  • Chris Hericks, snow ranger on Beaverhead Deerlodge NF, points to the lower of two surface hoar layers. We are finding similar layering throughout our entire forecast area. The top 18" of the snowpack is weak and will quickly become unstable when it snows. Photo: GNFAC

  • The crown is not visible (it is down and right) but the X marks the approximate spot the rider was found. Photo: GNFAC

  • The crown was measured 4-11 inches deep and 75 feet wide. Photo: GNFAC

  • Looking at a weak layer of facets that the avalanche propagated on. Photo: GNFAC

  • Looking at the crown from below. Photo: GNFAC

  • On Sunday, February 6, Gallatin Country Sheriff Search and Rescue and the GNFAC responded to a avalanche in Lionhead. A snowmobiler was killed on a small steep slope when a shallow avalanche carried him into a terrain trap of trees. Photo: GNFAC

  • This morning while ascending a line on Sawtooth Mountain (Lower Novocain) we triggered an avalanche (ASu-SS-R2-D2-O)  that caught and carried my partner an estimated 180M and partially buried him. His leg and hand were unburied and excavation of the head was done in less than 2 minutes of the incident. The avalanche only involved new snow from the last 48hrs and was triggered on a MF crust/facet combo 30cm down(formed 1/30/22). The avalanche was 30cm at its deepest and 20-30M wide and ran 250M. We were lucky to find both skis and poles a little ways downslope. No injuries were sustained.

    We both agree that we were trying to outsmart the instability that was present on steeper S facing terrain and should have turned around much sooner, we were very lucky. There was 30+cm HST in favored areas and the high winds from 1/31/22 formed some sensitive windslabs in specific areas. 

     

  • Graph of Snow Water Equivalent (SWE) at SNOTEL sites in the GNFAC forecast area from October 1, 2021 to January 30, 2022. It highlights the extended dry conditions in January that contributed to weak layers forming at the top of the snowpack. GNFAC

  • We rode at Lionhead today (Jan. 29, 2022) and found very weak snow on the surface which is not a problem now, but will be when we get more snow. Photo: GNFAC

  • Riders reported on 1/15/22: "Some surface hoar is forming on nearly every aspect at all elevations. over 1 cm thick in some areas." Photo: B. Rasmussen

  • Riders reported on 1/15/22: "Some surface hoar is forming on nearly every aspect at all elevations. over 1 cm thick in some areas." Photo: B. Rasmussen

  • Settlement rings around the base of trees near Cooke City, January 15, 2022. Photo: B. Fredlund

  • Ian Hoyer stands in the 7 foot deep snowpit we dug to look at layering and stability. Stability was good. We dug at 9300' off the Sawtelle Peak Road to keep tabs on stability since we put out warnings and basic information for this area on our Trip Planning page. Photo: GNFAC

  • The crown line is visible on the shaded face in the middle of the picture. Large avalanches released naturally during the week of 12/27 in the Centennial Mountains outside Island Park. Photo: GNFAC

  • Large avalanches released naturally during the week of 12/27 in the Centennial Mountains outside Island Park. Photo: GNFAC

  • Large avalanches released naturally during the week of 12/27 in the Centennial Mountains outside Island Park. Photo: GNFAC

  • Behind the sledders are deep piles of debris from an avalanche cycle a week ago in the Mt. Jefferson area near Island Park. Photo: GNFAC

  • A sled was recovered uphill of the 2 avalanche victims in the same area it was stuck. The sled was found with a probe line and is buried 3-4 feet deep. The avalanche crown can be seen in the upper slopes above them. Photo: GNFAC

  • The crown of the avalanche that killed two snowmobilers on December 27, 2021 was 300 feet wide and 4-5 feet deep. Photo: GNFAC

  • These are the two sites where the 2 snowmobilers were recovered. They were buried 4-5 feet deep in debris piles that measured 9 feet deep. Photo: GNFAC

  • Ian Hoyer stands next to the crown where we dug a snowpit and investigated the snow structure. The crown averaged 4-5 feet deep. Near his right knee is the layer of weak faceted snow that broke 40 cm above the ground. Above this layer was a thick slab of windblown snow. Photo: GNFAC

  • Dave Zinn of the GNFAC gets 3 layers breaking in his Extended Column Test. About 3 feet of snow fell in the last 4 days which got blown into wind slabs. The weight of the new snow is also creating instability on a weak layer of sugary facets near the ground. Photo: GNFAC

  • Located off Lionhead Ridge outside West Yellowstone, this natural avalanche likely released after the large storm ended Wednesday, December 15. This slope is SE facing and the crown is about 9,400 feet. Faceted snow at/near the ground was the likely weak layer that avalanched. Photo: GNFAC

  • Snowpack on Two Top Mtn. near Island Park, ID on 12/17/21. More than 3 feet of snow fell last week and it was right side up and generally stable. There is some weak snow and crusts near the ground, but we are not seeing signs that these layers are unstable yet. Photo: E. Knoff

  • A skier in the Southern Madison Range remotely triggered this avalanche in the Bacon Rind area from a flat bench above the slope. It broke over 50-75' away where the slope got steeper. Human-triggered avalanches are likely. Avoid steep terrain until the snowpack stabilizes. Photo: Anonymous 

  • From obs: 12/12/21: "Heavy wind loading from gusty SW winds and recent snowfall. Made for some touchy conditions. This was at 9100’ between Sage and Sunlight basins." Photo: JR Mooney

  • At Lionhead Ridge, strong winds are drifting snow into unstable slabs. On steep rollovers, we observed shooting cracks and one large collapse, or "whumph." With more wind and snow in the forecast, expect conditions to get more dangerous before they improve. Photo: GNFAC

  • New snow was blown into thick drifts that can be triggered by skiers or riders. Cracking like this is a sign that drifts are unstable and could slide on steeper slopes. Photo: GNFAC

  • From email (12/5/21) : "Small avalanche triggered while approaching ice climb in East fork of Hyalite basin. 

    Another D1 natural avalanche was observed later in the day similar aspect/elevation

    NE @7600’
    SS-AFu-D0.5-I"

    Photo: A. Schoening

  • Skiers on Mount Blackmore observed cracking within the freshly wind-loaded snow on a southeast-facing slope just below the ridge (11/24/21). Photo: J Schack

  • The snow was breaking 1 foot off the ground in the layer at the blue crystal card. Weak, sugary snow broke and propagated in the extended column test with 18 and 21 taps. We anticipate this weakness to get worse in the coming weeks. Photo: GNFAC

  • There was almost 2 feet of snow (60 cm) at 8800' on NE aspect of Sawtelle Peak. Weak snow (facets) is forming a foot off the ground and were breaking consistently in stability tests. Photo: GNFAC

  • Snowcover on Lionhead ridge begins at about 7,000' in elevation on 11/16. Snowmobiling or skiing from Targhee Pass looks very thin and patchy. Photo: GNFAC

  • Taken on 11/16, consistent snow on all aspects begins around 7,000 feet. 1.5-2 feet of snow is found above 8.500'. Photo: GNFAC

  • From e-mail 11/7/21: "...Once in airplane bowl we saw multiple large slides that ran last night, syn-storm. Most of which came down from the East face of Sac. A few 200-300’ wide and running the length of the bowl.,,, attached is a grainy cell phone pic of the slides in Airplane Bowl." -Anonymous.

  • From email 11/4/21: "...noticed two small wet loose avalanches in the east facing bowl between Pomp and Hardscrabble Peaks." Photo: H. Darby

Snowpit Profiles- Centennial Range

 

Select a snowpit on the map to view the profile image

Weather Forecast- Island Park

Extended Forecast for

10 Miles ESE Lakeview MT

  • Tonight

    Tonight: Mostly clear early, then becoming mostly cloudy, with a steady temperature around 44. South wind around 8 mph.

    Mostly Cloudy

    Low: 44 °F

  • Monday

    Monday: A chance of rain and thunderstorms, then showers and possibly a thunderstorm after 4pm.  High near 61. South southwest wind 8 to 14 mph, with gusts as high as 28 mph.  Chance of precipitation is 80%.

    Slight Chance
    Showers then
    Showers

    High: 61 °F

  • Monday
    Night

    Monday Night: A chance of showers and thunderstorms before 9pm, then a chance of rain between 9pm and midnight.  Mostly cloudy, with a low around 37. North wind 7 to 10 mph, with gusts as high as 23 mph.  Chance of precipitation is 50%.

    Chance
    T-storms then
    Mostly Cloudy

    Low: 37 °F

  • Tuesday

    Tuesday: Mostly sunny, with a high near 57. North wind 8 to 11 mph becoming southwest in the afternoon. Winds could gust as high as 22 mph.

    Mostly Sunny

    High: 57 °F

  • Tuesday
    Night

    Tuesday Night: Mostly clear, with a low around 34. Southwest wind 8 to 13 mph becoming southeast after midnight. Winds could gust as high as 22 mph.

    Mostly Clear

    Low: 34 °F

  • Wednesday

    Wednesday: Partly sunny, with a high near 54. Southeast wind 7 to 12 mph becoming southwest 16 to 21 mph in the afternoon. Winds could gust as high as 32 mph.

    Partly Sunny

    High: 54 °F

  • Wednesday
    Night

    Wednesday Night: A chance of rain before 3am, then a chance of rain and snow.  Mostly cloudy, with a low around 30. Breezy, with a southwest wind 14 to 22 mph, with gusts as high as 34 mph.  Chance of precipitation is 50%. Little or no snow accumulation expected.

    Chance Rain
    and Breezy
    then Chance
    Rain/Snow

    Low: 30 °F

  • Thursday

    Thursday: Snow likely.  Mostly cloudy, with a high near 37. West wind 16 to 21 mph, with gusts as high as 32 mph.

    Snow Likely

    High: 37 °F

  • Thursday
    Night

    Thursday Night: A chance of snow.  Mostly cloudy, with a low around 23.

    Chance Snow

    Low: 23 °F

The Last Word

We completed our investigation of the avalanche fatality at Ski Hill in Lionhead. A detailed report is HERE, the field video is on our YouTube channel and the incident is recorded on our Accident Reports page.