Trip Planning for Southern Madison

On March 15 We looked at the avalanche in Sunlight Basin/Taylor Fork that was triggered by a snowmobiler yesterday (Mar 14). It was 50' wide, 100' vertical, 2-3' deep hard slab with 8-9" new snow on top. Broke on weak facets buried in late January. Dirt layer from Feb 4 was visible 6-8" above weak layer. Bed surface was 3" to 1.5' deep of weak, sugary facets. Slope angle was 38-40+ degrees. 8800', WNW aspect. Photo: GNFAC

On March 15 We looked at the avalanche in Sunlight Basin/Taylor Fork that was triggered by a snowmobiler yesterday (Mar 14). It was 50' wide, 100' vertical, 2-3' deep hard slab with 8-9" new snow on top. Broke on weak facets buried in late January. Dirt layer from Feb 4 was visible 6-8" above weak layer. Bed surface was 3" to 1.5' deep of weak, sugary facets. Slope angle was 38-40+ degrees. 8800', WNW aspect. Photo: GNFAC

On March 15 We looked at the avalanche in Sunlight Basin/Taylor Fork that was triggered by a snowmobiler yesterday (Mar 14). It was 50' wide, 100' vertical, 2-3' deep hard slab with 8-9" new snow on top. Broke on weak facets buried in late January. Dirt layer from Feb 4 was visible 6-8" above weak layer. Bed surface was 3" to 1.5' deep of weak, sugary facets. Slope angle was 38-40+ degrees. 8800', WNW aspect. Photo: GNFAC

On March 15 We looked at the avalanche in Sunlight Basin/Taylor Fork that was triggered by a snowmobiler yesterday (Mar 14). It was 50' wide, 100' vertical, 2-3' deep hard slab with 8-9" new snow on top. Broke on weak facets buried in late January. Dirt layer from Feb 4 was visible 6-8" above weak layer. Bed surface was 3" to 1.5' deep of weak, sugary facets. Slope angle was 38-40+ degrees. 8800', WNW aspect. Photo: GNFAC

On March 15 We looked at the avalanche in Sunlight Basin/Taylor Fork that was triggered by a snowmobiler yesterday (Mar 14). It was 50' wide, 100' vertical, 2-3' deep hard slab with 8-9" new snow on top. Broke on weak facets buried in late January. Dirt layer from Feb 4 was visible 6-8" above weak layer. Bed surface was 3" to 1.5' deep of weak, sugary facets. Slope angle was 38-40+ degrees. 8800', WNW aspect. Photo: GNFAC

On Mar 14 A group of riders shared that they had triggered a 4' deep slide in a small pocket in Sunlight Basin of the Taylor Fork area. It was in an area with a relatively shallower snowpack, and broke on weak snow near the bottom of the snowpack. The rider that triggered it was going uphill and got stuck shortly after and noted the snowpack was much deeper there.

Another day of warm temps and clear skies allowed us to cover a lot of ground in the Southern Madisons. We rode into the Taylor Fork, up to the weather station, to the top of Carrot Basin, through Sage Basin, up and over into Cabin Creek, and all the way up to the head of Red Canyon.

There were a handful of small wet-loose avalanches on solar aspects that we noted throughout the day. While northerly aspects stayed cold, solar aspects became wet a couple inches down. Photo: GNFAC

Another day of warm temps and clear skies allowed us to cover a lot of ground in the Southern Madisons. We rode into the Taylor Fork, up to the weather station, to the top of Carrot Basin, through Sage Basin, up and over into Cabin Creek, and all the way up to the head of Red Canyon.

There were a handful of small wet-loose avalanches on solar aspects that we noted throughout the day. While northerly aspects stayed cold, solar aspects became wet a couple inches down. Photo: GNFAC

Photo taken Mar 1 by GNFAC

We also spotted an old wind slab avalanche (R1-D2) that broke earlier this week in Sunlight Basin. Photo: GNFAC

On Mar 1 we also spotted one older cornice-fall triggered avalanche in Sunlight Basin. Photo: GNFAC

On Mar 1 we also spotted two cornice-fall triggered (R2-D2) avalanches that broke earlier this week - one in Sunlight Basin and one in Sage Basin. Photo: GNFAC

On Mar 1 We also spotted one cornice-fall triggered (R2-D2) avalanche that broke earlier this week in Sage Basin. Photo: GNFAC

At the top of Carrot Basin, we saw a small avalanche (R1-D1) on a N aspect that likely broke yesterday on buried weak layers. Photo: GNFAC

At the top of Carrot Basin, we saw a small avalanche (R1-D1) on a N aspect that likely broke yesterday on buried weak layers. Photo: GNFAC

A rider triggered a huge avalanche in the uppermost reaches of Targhee creek on a north facing slope at 9200'

A rider triggered a huge avalanche in the uppermost reaches of Targhee creek on a north facing slope at 9200'

A rider triggered a huge avalanche in the uppermost reaches of Targhee creek on a north facing slope at 9200'

From IG message: "Getting word that a group triggered a decent slide today out at cabin creek. I’ll attach the coordinates to the general area, to the best of my knowledge.

44.86484, -111.22023

No burials. They were able to outride if. But thought I’d send coordinates in case you guys were gonna be in the area and wanted to check it out."

From IG message: "Getting word that a group triggered a decent slide today out at cabin creek. I’ll attach the coordinates to the general area, to the best of my knowledge.

44.86484, -111.22023

No burials. They were able to outride if. But thought I’d send coordinates in case you guys were gonna be in the area and wanted to check it out."

Snowmobile triggered avalanche likely on Saturday, Feb 22. It appeared that no one was caught or buried.

Snowmobile triggered avalanche that resulted in a partial burial with no injuries on Friday, Feb 21.

Snowmobile triggered avalanche that resulted in a partial burial with no injuries on Friday, Feb 21.

From IG message: "We remotely triggered this hillside in Taylor's fork yesterday [2/21] from the Ridgeline above it. We were looking for a safe spot to drop down when it released below us. Circled around for some pictures. The snow was pretty shallow, only 2-3 feet deep, and slid to the ground. South facing slope"

From IG message: "We remotely triggered this hillside in Taylor's fork yesterday [2/21] from the Ridgeline above it. We were looking for a safe spot to drop down when it released below us. Circled around for some pictures. The snow was pretty shallow, only 2-3 feet deep, and slid to the ground. South facing slope"

From IG message: "We remotely triggered this hillside in Taylor's fork yesterday [2/21] from the Ridgeline above it. We were looking for a safe spot to drop down when it released below us. Circled around for some pictures. The snow was pretty shallow, only 2-3 feet deep, and slid to the ground. South facing slope"

 There was a thin melt/freeze crust formed on solar aspects lower down (up to ~500 feet above the parking). Photo: BP

From email: "One of my crew was partially buried in an avalanche today(head about 1’ down, leg and arm still above snow) at approximately 13:10 hrs.  Slope was greater than 35 degrees, crown approximately 85 yards wide, over 3’ at its thickest point.  I believe it was a NE exposure with wind loading at the top.  I had a bad feeling about this slope and mentioned it to my crew and avoided riding on it until one rider ran out of gas and I had to help him.  Upon completion of task, I rode back to a spot that wasn’t as safe a vantage point as what I had previously stayed at, but the intention was we were all on our way out.  So I parked and within 30 seconds, I hear my friend yelling behind me. I turn and immediately think “oh he’s about to hit us”.  So, I  attempted to start up my sled, to no avail While watching behind me.  Suddenly, a massive “snow cloud” appeared about 30 yards above him and it took about 2-4 seconds to register that it was an avalanche and not another rider careening out of control at us.  By that time, it was too late to do anything.  The avalanche had reached the back of my friend and my sled, pushing us forward about 6 feet at 3-4mph.  After it stopped, I assessed 3 of four of our team was accounted for, and one (the one who yelled at us) was not.  He was partially buried by the front of the avalanche much like our sleds were.  Fortunately, within 5 seconds, I saw an arm and a leg sticking out of the snow and we had his airway and head cleared within about 20 seconds.   He was located approximately 10 yards from us.  "

From email: "One of my crew was partially buried in an avalanche today(head about 1’ down, leg and arm still above snow) at approximately 13:10 hrs.  Slope was greater than 35 degrees, crown approximately 85 yards wide, over 3’ at its thickest point.  I believe it was a NE exposure with wind loading at the top.  I had a bad feeling about this slope and mentioned it to my crew and avoided riding on it until one rider ran out of gas and I had to help him.  Upon completion of task, I rode back to a spot that wasn’t as safe a vantage point as what I had previously stayed at, but the intention was we were all on our way out.  So I parked and within 30 seconds, I hear my friend yelling behind me. I turn and immediately think “oh he’s about to hit us”.  So, I  attempted to start up my sled, to no avail While watching behind me.  Suddenly, a massive “snow cloud” appeared about 30 yards above him and it took about 2-4 seconds to register that it was an avalanche and not another rider careening out of control at us.  By that time, it was too late to do anything.  The avalanche had reached the back of my friend and my sled, pushing us forward about 6 feet at 3-4mph.  After it stopped, I assessed 3 of four of our team was accounted for, and one (the one who yelled at us) was not.  He was partially buried by the front of the avalanche much like our sleds were.  Fortunately, within 5 seconds, I saw an arm and a leg sticking out of the snow and we had his airway and head cleared within about 20 seconds.   He was located approximately 10 yards from us.  "

Snowmobile triggered avalanche in Teepee Basin. 

Large cornice fall triggered avalanche in Sage Creek, Photo: GNFAC

This snowpit on a SE aspect was made up of a dense slab of recent snow, sitting on top of many different layers of junky, faceted grains. Propagation was easy to find (ECTP 11, HS: 112).  Photo: GNFAC

We saw up to five recent avalanches from the last few days. 1-2 looked to have failed on PWLs, and the rest were wind slabs. Cornice collapses triggered at least two of these avalanches. Photo: GNFAC

Taylor Fork, Feb 13. Photo: GNFAC

We rode into the Taylor Fork on Feb 13, down into the bottom of Sunlight Basin, across Carrot Basin and to the Wilderness Boundary. We saw four persistent slab avalanches that likely broke last weekend or at the beginning of the week. All appeared to be snowmobiler-triggered R1-2, D1.5-2 avalanches at broke of the January layer of near-surface facets and surface hoar. Additionally, we saw one wind slab avalanche (R1, D1) in Sunlight Basin. This slide was fresh from this morning or yesterday. Photo: GNFAC

We rode into the Taylor Fork on Feb 13, We saw four persistent slab avalanches that likely broke last weekend or at the beginning of the week. All appeared to be snowmobiler-triggered R1-2, D1.5-2 avalanches at broke of the January layer of near-surface facets and surface hoar. Photo: GNFAC

We rode into the Taylor Fork on Feb 13, We saw four persistent slab avalanches that likely broke last weekend or at the beginning of the week. All appeared to be snowmobiler-triggered R1-2, D1.5-2 avalanches at broke of the January layer of near-surface facets and surface hoar. Photo: GNFAC

Buried layers of surface hoar often show up a stripe in a snowpit wall (other things such a thin melt-freeze crust can look similar but feel much differently). A snowmobiler-triggered avalanche in Sunlight Basin broke on this weak layer of feathery surface hoar. Photo: GNFAC

Relatively small persistent slab avalanche in Carrot Basin in the Taylor Fork. Photo: GNFAC

We rode into the Taylor Fork on Feb 13, We saw four persistent slab avalanches that likely broke last weekend or at the beginning of the week. All appeared to be snowmobiler-triggered R1-2, D1.5-2 avalanches at broke of the January layer of near-surface facets and surface hoar. Photo: GNFAC