Avalanche Decision Making — When It’s All on YOU

Do you know, for certain, that slope above you is safe, and far enough away?

A man heads out on a ski tour. He dies in an avalanche that appears so easy to predict and avoid you can hardly believe what you’re reading in the accident report. You glance away from your screen and reflect: “Could this have been me?”

First, let me take a moment to offer condolences to the family and friends of the person I write about below. (I’ll not mention names, with respect to Google search results landing here instead of obits and such). After a half century of ski touring I’ve known all too many people who have perished in avalanches. Every one of these individuals is a tragedy in so many ways: lost potential; orphaned children; loved ones left to grieve and shout why to the empty sky. And then the ancillary deaths brought on by the unrequited sadness of the living; alcoholism, depression, more. If I think on it too much, I fall into a profound sadness. It’s as if we’re in a decades-long battle, replete with casualties, PTSD, all the bad. While there is nothing that can magically erase this sadness, treating these events as learning moments is a way of helping others survive the battle. Or avoid the battle entirely. That’s why, at the risk of being accused as a second-guesser, I write these sorts of posts.

The Mount Trelease accident here in Colorado earlier this winter is today’s case in point. I was the person wondering, “Could this have been me?”

I’ve ski toured Trelease, and know firsthand that the more conservative uphill route, while mostly safe, leads to a runout zone below an avalanche path that produces potentially killer slides. I remember looking at that path looming above me and my partner, thinking, are we far enough away? I figured we were — based on instinct and the size of the trees we were still near. But I couldn’t be sure, since it’s impossible to determine slope angles while looking directly up a slope without some sort of instrumentation — and the only way to be sure you’re out of an avalanche run-out is by knowing the angles. Specifically, something called the “alpha angle.” More on that later. For now, what happened up there? And how about we use this unfortunate event as a self check?

The accident
As gleaned from the CAIC report, a solo splitboarder climbed a well-used skin track to the Trelease avalanche runout zone, made his own track into an area more exposed to runout, then perhaps continued up the steeper portion of the path. The path avalanched. The man was entrained in the slide and died.

When other skiers in the area saw the avalanche deposition and the errant skin track, they executed a good Samaritan beacon search. With no success. Eventually, the authorities figured out who the victim probably was and triangulated his cell phone. They phoned the resulting coordinates to the rescuers on-scene, who used the coordinates to locate the victim. He had no beacon and was wearing an inflated airbag backpack. The report says that the victim was not totally buried, though his head was under the snow.

As is often — and understandably — the case with CAIC accident reports, there is no mention of the mechanism of death. I’m assuming it was trauma, perhaps from impact with a tree. But I suppose he could have been pinned in such a way as to not be able to free his head from the snow. In any case, one can’t deny that if he’d had a transmitting beacon, the good Samaritan searchers might have found him soon enough to save him.

And there I go. I just committed that annoying and possibly deadly canard that’s prevalent in avalanche analysis, communication and even education. I focused on the technology, falling prey to the mantra chanted by us soldiers as we march to war: beacon-shovel-probe-beacon-shovel-probe!! When really, what was going on here?

Analysis
For reasons we will never know, a man chose to venture into the deadly maw of a potential avalanche — when all signals indicated doing so was a profoundly flawed judgement call. Read the “Backcountry Avalanche Forecast” section of the report and you’ll know why I say this. But more, the signals on the ground were there as well. Glance at the photos included with the report. Anyone with a basic knowledge of avalanches — which I assume this gentleman had, based on his abundant days out — would have known by the chalky, thick, wind-sculpted appearance of the snow that this slope was likely primed for a slide.

So if I’m not going to rant about beacons, shovels and airbags, and we’ve established this was an obvious avalanche slope, what’s my take?

First, there’s solo ski touring. Sure, it is axiomatic that heading out by your lonesome has inherent risks, e.g., lay there with a broken leg and your InReach battery goes out, what do you do, crawl? More, there’s the issue of how a solo skier depends on the social contract, consequently placing others at risk in the event of a rescue.

But we’re not talking ethics here, just the basics of avalanche safety. Is solo skiing extra risky in that regard? Not inherently. As solo skiers often point out, when done with fanatical avoidance of avalanche danger, solo skiing is likely as safe as skiing with a group. Anecdotal perusal of accident reports appears to bear this out. Everywhere I’ve toured, from the Tetons to the Alps, I’ve seen an astounding number of solo backcountry skiers. Anecdotally speaking, I’ve not seen them represented in the accident reports any more than other demographics. (That’s not saying I recommend it.)

Self analysis
So let’s move on from solo skiing as a safety issue, and instead use it as a tool of self analysis. (Please know I intend the following for newcomers to backcountry skiing. If you’re seasoned, as many WildSnow readers indeed are, apologies if I wax sophomoric.)

Put yourself on Mount Trelease the day of the accident, by yourself. Not in the victim’s shoes — we’ll do that in a moment — for now stay in your own boots.

As you gear up at the trailhead, you have no partners to negotiate with (known in avalanche classes as group discussion) no one who’s more expert than you, nobody to call BS on poor decisions. You’re on your own. It is all on you — the refiner’s fire. Have you checked the avalanche forecast? The “Know Before You Go” PR told you to, so you did. But what do you “know?” Did you really understand what you read, and thus you know how dangerous this well known Mount Trelease avalanche slope actually is — today?

Now put yourself in the victim’s boots. When you reach that lower angled area below the runout zone, where the well-used skin track has led you, are you certain it’s a safe zone, or do you just assume, because that’s where the skin track goes, and the ground is nearly flat? Then, when you decide to skin higher in the runout, do you still assume you’re far enough below the potential avalanche? For some skiers, there might be a third answer: you just don’t care. But that wasn’t this guy. He spent the money on an airbag backpack. He deployed it. His social media presents a joyful individual who delighted in big servings of snowy life. He cared. But did he know? I like to think he did, and he was doing what many of us have done, and figured he’d touch the dragon one more time.

But what if he didn’t know? What if he’d listened to the media hype about airbags, and figured that buying one improved his odds to the extent he could justifiably travel avalanche slopes solo, without a beacon? What if he’d never really learned how to identify how far an avalanche might run across the lower angled ground of the runout? What if he’d never developed what avalanche expert Bruce Tremper calls “avalanche eyeballs,” the ability to effortlessly and constantly see all terrain in terms of avalanche potential? What if he’d never developed a firm personal philosophy of physical risk versus reward?

Again, I’ll give this unfortunate man the benefit of the doubt. I’ll assume he knew what he was doing, had considered a risk/reward equation, and chose to continue.

How about you? Are you prepared to make your own calls in such a situation — as if you were skiing solo? If not, who are you depending on as your proxy? A guide? A friend? A friend of a friend?

Epilog: Our avalanche quiz might be a bit long of the tooth now, but can still be helpful. I tested, it still appears to work.

Oh, and what about my original question: “Could this have been me?” Way back in the past, yes. Now, probably not. Probably is the operative word. When my friend and I were standing below that path, it’s possible we were in the runout zone. Though I don’t think so. Thing is, we could have known for sure if we’d had a means of determining exact angles, and used the concept of alpha angle.

Readers seeking to learn the nuances of avalanche safety might take note of the CAIC’s mention of alpha angle in the Trelease avalanche report: 23 degrees. For reasons I can’t fathom, the idea of alpha angle elicits all sorts of negative reactions from backcountry skiers. Maybe “alpha angle” sounds too bookish, or those offended just can’t figure out how to apply the concept.

In a nutshell: Alpha angle is what you intuitively use when you look at an avalanche slope and guess at a safe route skirting the runout zone. In other words, you make a judgement call on how far the beast will gallop. Thing is, you can get more scientific than a guess. Turns out most snow climates have average alpha angles. Know the numbers, break out your inclinometer (or get real good at guessing), and you can make valid determinations as to where to safely stand or cross at the base of a slope, or for that matter where to build a house. Learn the details here.

Lou Dawson

WildSnow.com publisher emeritus and founder Lou (Louis Dawson) has a 50+ years career in climbing, backcountry skiing and ski mountaineering. He was the first person in history to ski down all 54 Colorado 14,000-foot peaks, has authored numerous books about about backcountry skiing, and has skied from the summit of Denali in Alaska, North America’s highest mountain. For more about Lou, please see his personal website at https://www.loudawson.com/ (Blogger stats: 5 foot 10 inches (178 cm) tall, 160 lbs (72574.8 grams).

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