Regional Conditions for Lionhead Range

Skiers saw this 2-4' deep natural crown on Sunday 2/23/20. Photo: from IG @skishot

From IG #gnfacobs post: "An avalanche from early Tuesday (02/18) morning caused by a natural cornice fall. Note the step down partway down the path. ENE @ 9700. Ran 1300’." Photo: A. Whitmore

Slide in Taylor’s Fork, crown of about 5-6’ and about 100' wide. Human triggered. Photo: Matt Seifert

We rode into Lionhead and found good stability. A sledder highmarked up the hill and then came down right next to us, confirming our results. Wind-loading from yesterday is still a concern, and so are the facets near the ground, although less so than a couple weeks ago. Photo: GNFAC

We saw a group of six snowmobilers who said they triggered these slides in McAtee Basin on the left side of the meadow on Saturday, Feb 8. I didn't see tracks up on the hill or sidehill tracks so they may have triggered the slope from the flats below. The debris runs all the way to bottom of the hill. Photo: K Peaslee

We saw a group of six snowmobilers who said they triggered these slides in McAtee Basin on the left side of the meadow on Saturday, Feb 8. I didn't see tracks up on the hill or sidehill tracks so they may have triggered the slope from the flats below. The debris runs all the way to bottom of the hill. Photo: K Peaslee

We saw a group of six snowmobilers who said they triggered these slides in McAtee Basin on the left side of the meadow on Saturday, Feb 8. I didn't see tracks up on the hill or sidehill tracks so they may have triggered the slope from the flats below. The debris runs all the way to bottom of the hill. Photo: K Peaslee

"Noted two SS-D1.5/2 naturals (presuming based on lack of any sort of tracks) on Wheeler, typical spots for these conditions, both SE aspect around 8000'." Photo: G. Antoniolli

"Noted several avalanches (NW aspect ~ 8800') off of Elephant that traveled quite far into the trees where the summer trail typically runs, all appear to be new snow, D1- D2 in size, average 2' crowns, running on old/new interface from  Feb 2. They appear to have run midstorm, sometime yesterday (photos 1,2,3).  Above 9000', W Winds were crafting fresh wind slabs that were most reactive on a midstorm crystal/density change that buried a layer of stellars ~ 1' deep in shallower spots,  topped with denser snow." Photo: G. Antoniolli

"Natural avalanche. North facing slope. Around half mile wide. Photos don't show half of the slide. Broke on the ground facets. Crown was between 3 and 15 feet deep. We didn't get a photo of the deepest crown. Ripped trees out around 5" diameter." Photo: Reed Malmstrom

"Natural avalanche. North facing slope. Around half mile wide. Photos don't show half of the slide. Broke on the ground facets. Crown was between 3 and 15 feet deep. We didn't get a photo of the deepest crown. Ripped trees out around 5" diameter." Photo: Reed Malmstrom

"Natural avalanche. North facing slope. Around half mile wide. Photos don't show half of the slide. Broke on the ground facets. Crown was between 3 and 15 feet deep. We didn't get a photo of the deepest crown. Ripped trees out around 5" diameter." Photo: Reed Malmstrom

On private property, this small child triggered a slide and climbed out of the debris, not buried. A very close call! On the heels of this large snowstorm there are possibilities of children getting caught on road cuts or any open hill!  Photo: Anonymous

We triggered this avalanche in the second Yellow Mule off Buck Ridge on 2/6/2020 It is on a small roll/cornice "in the flats". It broke within the current 2-3' storm snow. Photo: GNFAC

A snowmobiler triggered this avalanche in the second Yellow Mule off Buck Ridge on 2/6/2020 It is on a small roll/cornice "in the flats". It broke within the current 2-3' storm snow. Photo: GNFAC

We saw this natural crown that broke within the current 2-3' storm on a small terrain feature. It is in the second Yellow Mule off Buck Ridge on 2/6/2020. Photo: GNFAC

Hebgen/West Yellowstone snow rangers and Montana State Parks installed this beacon checker at the trail into Lionhead Ridge. It is a great asset to promote avalanche awareness in our area. Photo: J. Norlander

From riders involved: "Yesterday we were the ones in the big sky avalanche. There was no markings on the spot we were climbing. Further down the mountains there were climbs at the same angles of this slope. Thankfully the rider was above the slide when it started and managed to stay on top. Rider walked down the debris and we found the sled lower down in the trees. No injuries." Photo: Anonymous

From riders involved: "Yesterday we were the ones in the big sky avalanche. There was no markings on the spot we were climbing. Further down the mountains there were climbs at the same angles of this slope. Thankfully the rider was above the slide when it started and managed to stay on top. Rider walked down the debris and we found the sled lower down in the trees. No injuries." Photo: Anonymous

From obs. form: "[slope] Was marked up previously. We parked out near the bottom and a few guys not in our group start climbing. So we watch them climb. It breaks out. Guy ditches the sled and manages to stay up top. Sled goes down with the slide. Then the snow breaks in 2 other spots creating more slides." Photo: C. Carlson

The 10' deep avalanche in 2nd Yellowmule is almost completely filled in now. In its place are massive cornices overhanging the slope. Give these beasts a lot of extra room as they can break back far from the edge. Photo: GNFAC

Ian Hoyer stands in a snowpit in Beehive Basin. Avalanches are getting harder to trigger, but in more shallow areas we are still finding a poor snowpack structure. The stability test scores are climbing higher, but still propagating and we did not ski the adjacent slope. Photo: GNFAC

February 1, King and Queen of the Ridge at Bridger Bowl (fundraiser). This is the Friends of the Avalanche Center’s second biggest fundraiser of the year. Come on out and help us raise money by hiking and skiing laps on the ridge. Prizes, camaraderie and a good time is guaranteed. Register with Bridger to hike in the event, and create a pledge page to raise funds with your Ridge laps.

Small snowmobiler triggered avalanche in McAtee Basin. From Instagram: "I watched a snowmobiler set this avalanche off today" T. Chamberlain

Small snowmobiler triggered avalanche in McAtee Basin. From Instagram: "I watched a snowmobiler set this avalanche off today" T. Chamberlain

From email:

"I wanted to make you aware of a snowmobile triggered slide in Lionhead today. Fortunately, I was not injured, was able to stay completely on top, climbed through the majority of the snow wash after seeing it begin to break, and relatively slowly slid down with the last of the moving snow while still on the machine. When I came to a stop, I stood up and was completely free of the snow. Our group is trained in avalanche safety, practiced beacon use prior to leaving town in the morning, were wearing avy gear, and were very fortunate that this ended up the way it did. 

A clear reminder that this can happen to any of us and to be careful out there."

Photo: Anonymous 

Snowmobiler triggered avalanche near Reas Peak on Sunday, 1/19/20. He was able to ride through it uphill. Photo: R. Gravatt

Snowmobiler triggered avalanche near Reas Peak on Sunday, 1/19/20. He was able to ride through it uphill. Photo: R. Gravatt

From obs: "I was on the west side of Pioneer Mtn digging a pit for YC Ski Patrol. I heard a few groups of snowmobiles cruising around the foothills of cedar. I turned and saw two snowmobilers cresting the ridge above the slide pictured as the debris was settling down. The sledders enjoyed the view for a few minutes before turning back the way they came and stumbled upon the slide they had unknowingly triggered. They skirted around the side of the crown and stopped for a few minutes. Based on the height of the rider off his sled, I would estimate the crown to be roughly 10’ at its max height. NE aspect below Cedar" Photo: J. Marcinko

Fresh wind slabs releasing naturally near the top of Lionhead Ridge. Photo: GNFAC

This was an older slide on Lionhead Ridge. It broke 3 to 4 feet deep and propagated on a buried weak layer. Probably from a few days ago. Photo: GNFAC

With only 3" of new snow overnight, a cornice triggered a large avalanche at Lionhead early this morning. It broke 3 to 4 feet deep and propagated on a buried weak layer. This is the only stability test we need today, human triggered avalanches possible and the management strategy is to avoid steep slopes or be clear about your risk tolerance if you are poking into avalanche terrain. Photo: GNFAC

With only 3" of new snow overnight, a cornice triggered a large avalanche at Lionhead early this morning. It broke 3 to 4 feet deep and propagated on a buried weak layer. This is the only stability test we need today, human triggered avalanches possible and the management strategy is to avoid steep slopes or be clear about your risk tolerance if you are poking into avalanche terrain. Photo: GNFAC

The crown of this snowmobiler triggered avalanche tapered to a thin slab. These thin areas of the slope are prime zones to trigger a slide from. Photo: GNFAC

Natural avalanche observed on 1/17 in Airplane Bowl off of Lionhead Ridge.

Photo: P. Smith

The snowpack in Lionhead is a respectable 6' deep. The facets near the ground are gaining strength and we were unable to get them to break in our tests. Stability is improving! Photo: GNFAC

We visited the avalanche that was triggered by a snowmobiler and partially buried 2 people on January 4th. The crown was 10 feet at the deepest part. Photo: GNFAC

We visited the avalanche that was triggered by a snowmobiler and partially buried 2 people on January 4th. The crown was 10 feet at the deepest part. Photo: GNFAC