Tracked-out slopes that avalanche

[Bad Bob]

You guys all know this, but small trees all leaning down slope are a pretty big tell about snow load on a slope. A very good place to be away from and not below.

 

[Truberski]

This is an unfortunate phenomenon at what used to be called The Canyons before Vail and PCMR gobbled them up. They had three backcountry gates and one was right on top of and a short hike up from a lift. You could see into the terrain from the chairlift and hear all the people hooting and hollering in the powder. There were two deaths in that terrain when we lived there over 10 years and lots of close calls. And, it wasn’t controlled but always pretty tracked out. No idea what their current policy is and if the gates still exist or not. The Canyons often had that terrain as the backdrop of their marketing photos/ads which always struck me as misleading and ironic.

It was a humbling experience when I took Avy 1 class and realized how stupid and lucky I had been in that and similar terrain as a tourist and UT resident. Trees and tracks definitely give one a false sense of security and I agree that the thinly spaced/steep trees that we all love aren’t any better. Actually worse with likelihood of body trauma from collision with or pinning into tree.

I was more of a “meadow hopper” once I got more avy training and experience and was a challenge finding like minded partners (besides my spouse). Everyone has different risk level tolerances and the majority (at least in US) ducking Ropes and going out gates to semi-tracked terrain have no clue. Not a problem in my current locale (VT) but have needed to put some healthy fear in my kids for our Rocky Mountain vacations so they know when to say “no” and that ducking ropes can have real consequences (unlike VT).

 

[raisingarizona]

If there are trees present: Do they help prevent avalanches? OR Are the trees growing here because the avalanches avoid this area?

I think you get both effects. Trees show where the avalanches are less prevalent. AND Stands of trees help stabilize the snowpack and prevent avalanches.

Like most questions regarding snow science the answer is well yes and no. They can tell you where the really big slides that take out stands of trees happen but there's plenty of small slides that happen in the trees. I don't remember the numbers exactly but most avalanche fatalities happen in slides much less than 300 feet in length and it's often in the trees.

 

[ZionPow]

Trees do prevent avalanches to happen, but the thing is, they need to be close together to have that effect.

Anchors in the snowpack, such as rocks, bushes and trees do have to be fairly dense to stabilize a slope. They can hold hard slabs in place more effectively than soft slabs if densely spaced. The anchors also create stress concentration points in the snowpack so fracture lines tend to run from one anchor to another. Anchors do tend break up the continuity of a slab so fractures don’t propagate as far without anchors.

Tracked out slopes tend to slide when temperatures warm rapidly enough to affect the snowpack structure. The other phenomenon that happens is that people tend to begin skiing on a less reactive aspect of a slope and as it gets tracked out, they start skiing a more fragile aspect to get fresh tracks. Many snowpacks exhibit a significant amount of spatial variability and the only way to know is to dig multiple snow study pits on different aspects and locations. And to make it more complex, the snowpack is always changing!

 

[locknload]

This is an unfortunate phenomenon at what used to be called The Canyons before Vail and PCMR gobbled them up. They had three backcountry gates and one was right on top of and a short hike up from a lift. You could see into the terrain from the chairlift and hear all the people hooting and hollering in the powder. There were two deaths in that terrain when we lived there over 10 years and lots of close calls. And, it wasn’t controlled but always pretty tracked out. No idea what their current policy is and if the gates still exist or not. The Canyons often had that terrain as the backdrop of their marketing photos/ads which always struck me as misleading and ironic.

It was a humbling experience when I took Avy 1 class and realized how stupid and lucky I had been in that and similar terrain as a tourist and UT resident. Trees and tracks definitely give one a false sense of security and I agree that the thinly spaced/steep trees that we all love aren’t any better. Actually worse with likelihood of body trauma from collision with or pinning into tree.

I was more of a “meadow hopper” once I got more avy training and experience and was a challenge finding like minded partners (besides my spouse). Everyone has different risk level tolerances and the majority (at least in US) ducking Ropes and going out gates to semi-tracked terrain have no clue. Not a problem in my current locale (VT) but have needed to put some healthy fear in my kids for our Rocky Mountain vacations so they know when to say “no” and that ducking ropes can have real consequences (unlike VT).

Dutch's Draw...right out the 9990 gate. I believe that is closed now. You can get there but have to do a long skin and much more roundabout. Notoriously unstable in spots. Talked to a patroller right there and he was telling me that of the people going out the gate...he was using his beacon in receive mode to see how many people heading out the gate were pinging...it was something like 25%. Recipe for problems.

 

[ZionPow]

Dutch's Draw...right out the 9990 gate. I believe that is closed now.

There was quite a bit of controversy when Park City Resort decided to close this gate. The terrain is on forest service land but the gate was on Park City resort property so they were allowed to close the gate. Most Utah resorts have an open gate policy to allow guests to access forest service land as long as they do not enter closed avalanche terrain inside the resort. This area is still accessible but as @locknload stated, it is now much more difficult to access.

 

[locknload]

There was quite a bit of controversy when Park City Resort decided to close this gate. The terrain is on forest service land but the gate was on Park City resort property so they were allowed to close the gate. Most Utah resorts have an open gate policy to allow guests to access forest service land as long as they do not enter closed avalanche terrain inside the resort. This area is still accessible but as @locknload stated, it is now much more difficult to access.

I remember how much controversy there was. Correct me if I'm wrong, but the main issue was not just the temptation of easy access BUT if/when a rescue needed to be executed, the likelihood that ski patrol might have to assist immediately while they waited for search and rescue meant that PCMR/Canyons would be impacted if they had to commit resources. I'm sure their lawyers didn't want to sign off on that. All this reinforces that there is no "side country"..only in bounds terrain and unpatrolled backcountry. BTW...I remember the Canyons Red Pine chutes avalanche in 2007 that killed a skier inside the resort boundary. Extremely unusual.

 

[raisingarizona]

Anchors in the snowpack, such as rocks, bushes and trees do have to be fairly dense to stabilize a slope. They can hold hard slabs in place more effectively than soft slabs if densely spaced. The anchors also create stress concentration points in the snowpack so fracture lines tend to run from one anchor to another. Anchors do tend break up the continuity of a slab so fractures don’t propagate as far without anchors.

Tracked out slopes tend to slide when temperatures warm rapidly enough to affect the snowpack structure. The other phenomenon that happens is that people tend to begin skiing on a less reactive aspect of a slope and as it gets tracked out, they start skiing a more fragile aspect to get fresh tracks. Many snowpacks exhibit a significant amount of spatial variability and the only way to know is to dig multiple snow study pits on different aspects and locations. And to make it more complex, the snowpack is always changing!

That's a great post! I'm going to add that with a gnarly PWL it sometimes makes no rhyme or reason. I feel like there's been slides rip out of heavily skied slopes with moguls even for no explainable reason. It's like the 327th (random number to prove point) skier was apparently the straw that broke the camels back. When there's rot like that it's time to reel it in and ski extremely conservatively.

I took an avie 1 21 years ago in Silverton. We had an engineer in the group who would insist on concrete answers from the instructors. I get it, that's how his brain works and he likes absolutes as that's what works for his profession but it was a little entertaining to see him struggle with the complexities of snow pack science.

 

[ZionPow]

if/when a rescue needed to be executed, the likelihood that ski patrol might have to assist immediately while they waited for search and rescue meant that PCMR/Canyons would be impacted if they had to commit resources.

You are correct. Technically, Park City Ski Patrol is not required to respond to an accident that occurs out of bounds. But in reality they have the equipment, training, knowledge and are in close proximity to respond if an accident happens. Most professional ski patrollers train many years to be able to respond in a safe and rapid manner in case of an accident and most of us at my resort are members of the Wasatch Backcountry Rescue team. Most patrollers are very anxious to respond in a situation like that because we know that if a person is buried, timing is essential to the outcome of a rescue versus a recovery. I have personally responded to avalanche searches out of bounds near my resort and it does take significant resources. We typically respond with transceiver, recco and Avy dog search teams. When this happens, we have to move resources to the areas that have been depleted due to the out of bounds search which can possibly leave patrol resources very thin in some areas. We do not have extra patrollers sitting around in case an out of bounds incident happens. Sometimes we have to deploy extra explosives in the area of the accident so we can safely start the search. I don’t know all of the specific details about the Park City decision to close that gate but I understand their concerns.

 

[Truberski]

I remember how much controversy there was. Correct me if I'm wrong, but the main issue was not just the temptation of easy access BUT if/when a rescue needed to be executed, the likelihood that ski patrol might have to assist immediately while they waited for search and rescue meant that PCMR/Canyons would be impacted if they had to commit resources. I'm sure their lawyers didn't want to sign off on that. All this reinforces that there is no "side country"..only in bounds terrain and unpatrolled backcountry. BTW...I remember the Canyons Red Pine chutes avalanche in 2007 that killed a skier inside the resort boundary. Extremely unusual.

I also remember the Red Pine Chute incident and super strange for an inbounds slide and fatality. That was my home resort that season and I loved poking around that zone of the resort. It was a commitment to get to and back to the top from that terrain but often best snow at the resort and some really fun tech‘ish lines.

But to a point someone else made, this is not an exact science with crazy amount of variables and variability within an intended slope/run. I trust the professionals and don’t think twice about inbound, controlled terrain but am paranoid and picky in the BC.

 

[Truberski]

Dutch's Draw...right out the 9990 gate. I believe that is closed now. You can get there but have to do a long skin and much more roundabout. Notoriously unstable in spots. Talked to a patroller right there and he was telling me that of the people going out the gate...he was using his beacon in receive mode to see how many people heading out the gate were pinging...it was something like 25%. Recipe for problems.

Yep, that’s the spot I had in mind. My first Avy Class was hosted by the head of Canyons patrol (at time) and that was the gate we used for our class. He was clearly disgusted by the ignorance and apathy of most going through the gates, and I recall him berating a couple who was hiking up with their young son. No beacon, no training, and no clue.

I would miss that gate if we still lived there because it was soooo easy but the others make more sense to filter out the masses. A skin track is a wonderful filter…..

 

[locknload]

You are correct. Technically, Park City Ski Patrol is not required to respond to an accident that occurs out of bounds. But in reality they have the equipment, training, knowledge and are in close proximity to respond if an accident happens. Most professional ski patrollers train many years to be able to respond in a safe and rapid manner in case of an accident and most of us at my resort are members of the Wasatch Backcountry Rescue team. Most patrollers are very anxious to respond in a situation like that because we know that if a person is buried, timing is essential to the outcome of a rescue versus a recovery. I have personally responded to avalanche searches out of bounds near my resort and it does take significant resources. We typically respond with transceiver, recco and Avy dog search teams. When this happens, we have to move resources to the areas that have been depleted due to the out of bounds search which can possibly leave patrol resources very thin in some areas. We do not have extra patrollers sitting around in case an out of bounds incident happens. Sometimes we have to deploy extra explosives in the area of the accident so we can safely start the search. I don’t know all of the specific details about the Park City decision to close that gate but I understand their concerns.

Makes perfect sense. In any case....thank you for the rescue work you do. The other piece of all this is that if ignorant and/or untrained Individuals take risks that get them in trouble...search and rescue people are going to go help them regardless of how they got there. The risk of secondary slides and other hazards puts search and rescue in danger and that also sucks.

 

[locknload]

Yep, that’s the spot I had in mind. My first Avy Class was hosted by the head of Canyons patrol (at time) and that was the gate we used for our class. He was clearly disgusted by the ignorance and apathy of most going through the gates, and I recall him berating a couple who was hiking up with their young son. No beacon, no training, and no clue.

I would miss that gate if we still lived there because it was soooo easy but the others make more sense to filter out the masses. A skin track is a wonderful filter…..

"A skin track is a wonderful filter….."
1000%.

 

[locknload]

I also remember the Red Pine Chute incident and super strange for an inbounds slide and fatality. That was my home resort that season and I loved poking around that zone of the resort. It was a commitment to get to and back to the top from that terrain but often best snow at the resort and some really fun tech‘ish lines.

But to a point someone else made, this is not an exact science with crazy amount of variables and variability within an intended slope/run. I trust the professionals and don’t think twice about inbound, controlled terrain but am paranoid and picky in the BC.

Some great terrain and snow in there...really liked that spot. Man...I haven't skied over there in years and I don't ski PCMR anymore b/c I'm on the Ikon pass.

 

[raisingarizona]

Makes perfect sense. In any case....thank you for the rescue work you do. The other piece of all this is that if ignorant and/or untrained Individuals take risks that get them in trouble...search and rescue people are going to go help them regardless of how they got there. The risk of secondary slides and other hazards puts search and rescue in danger and that also sucks.

As I’ve gotten older I’ve changed my perception of risk quite a lot. It’s selfish to take unnecessary risky chances in the backcountry. If shit goes south you’re going to ruin your partners day, put rescue personnel in danger and probably keep ski patrol from doing their actual job and helping people skiing in the area. It’s kind of a crappy, self centered thing to do.

16 years ago I was in a slide in telluride. I was skiing a closed area and the slide took me off a cliff in to an open area below. There were two local teens puffing some weed a few feet from where the slide poured over the rocks. I could have killed them. Thank god I didn’t but it was close. I haven’t poached a closed area like that ever again.

people aren’t very good at thinking of how their behavior can impact others. I was a dumb ass kid for a good long while, thankfully I made it this far.

 

[locknload]

As I’ve gotten older I’ve changed my perception of risk quite a lot. It’s selfish to take unnecessary risky chances in the backcountry. If shit goes south you’re going to ruin your partners day, put rescue personnel in danger and probably keep ski patrol from doing their actual job and helping people skiing in the area. It’s kind of a crappy, self centered thing to do.

16 years ago I was in a slide in telluride. I was skiing a closed area and the slide took me off a cliff in to an open area below. There were two local teens puffing some weed a few feet from where the slide poured over the rocks. I could have killed them. Thank god I didn’t but it was close. I haven’t poached a closed area like that ever again.

people aren’t very good at thinking of how their behavior can impact others. I was a dumb ass kid for a good long while, thankfully I made it this far.

Well said. The good news is we can all evolve our thinking if we are open to it. Scary story! How far of a drop and I assume you were mostly uninjured? Please share more if you are willing. It must be a very harrowing thing to recall. The scary thing about slides...is that everything is fine until suddenly its not. Wow.

 

[raisingarizona]

Well said. The good news is we can all evolve our thinking if we are open to it. Scary story! How far of a drop and I assume you were mostly uninjured? Please share more if you are willing. It must be a very harrowing thing to recall. The scary thing about slides...is that everything is fine until suddenly its not. Wow.

The drop was probably only about 30-35 feet and the slide wasn’t super huge but it went to the ground. It was dumping sideways and the snowpack was completely upside down. It beat the shit out of me. The power was intense. My right ski came off as I was launched into the air. There was a sort of dihedral that I got slammed in to. After I hit the ground my left ski was pulling me under and as the moving snow got up to my chest I torqued it off, thank goodness for those shit toe wings on the old markers. I had the dins set to 17 or 18 (green springs). Then it came to a stop. There was a total strainer of forest just below from there. That’s all I saw going into the air off the cliff, I thought I was dead.

I couldn’t get around much for two weeks because I was so sore. I must have used every muscle and energy that I possibly could to try and survive.

This happened in the Poison Spider area on Gold Hill in Telluride. That’s the major cliff band area just to viewers left as you’re riding the chair up.

 

[locknload]

The drop was probably only about 30-35 feet and the slide wasn’t super huge but it went to the ground. It was dumping sideways and the snowpack was completely upside down. It beat the shit out of me. The power was intense. My right ski came off as I was launched into the air. There was a sort of dihedral that I got slammed in to. After I hit the ground my left ski was pulling me under and as the moving snow got up to my chest I torqued it off, thank goodness for those shit toe wings on the old markers. I had the dins set to 17 or 18 (green springs). Then it came to a stop. There was a total strainer of forest just below from there. That’s all I saw going into the air off the cliff, I thought I was dead.

I couldn’t get around much for two weeks because I was so sore. I must have used every muscle and energy that I possibly could to try and survive.

This happened in the Poison Spider area on Gold Hill in Telluride. That’s the major cliff band area just to viewers left as you’re riding the chair up.

I had to go look it up on the map. Wow...scary as F!!! 30 to 35 feet sounds big enough to me. Looking at the trail map (its been a decade since I skied there) I see a big open area with some rocks (cliffs) drawn on the map below the trail called Dynamo. Is that it? I had forgotten how high Telluride tops out at...12,515! Such a great place to ski.

 

[KingGrump]

I am not a backcountry skier. However, I have seen my share of inbound avalanches to have lots of respect for Mother Nature.

Few seasons back, probably the 2nd or 3rd season TSV opened Ernie's. A huge spring slide happened. Probably about 1,500 vertical feet in very dense trees. Went across the Return Trail into Pioneer Glade. Took down lots of trees. Really scary.
Ernie's is a very open glade now rather than the dense trees when it first opened.
On the same day, the area on the uphill side of Jean's also slid. That section is the new Etches Glade.

Mother Nature can be brutal when one least expects.

North American and Ernie's is the tree area on the skier's right of the lift line (Al's).

 

[pais alto]

Viewing the wreckage of that slide in Ernie’s was sobering. It took out an awful lot of big old trees.

If it’s open enough to ski, it’s open enough to slide.