A learning experience on Mt Hood

After an unusually warm week with valley temperatures reaching upwards of 70 degrees, a late season storm was approaching Mt Hood and appeared to have the potential to deliver a significant powder punch on Monday. The forecast was calling for 8-12 inches overnight with temperatures in the low 20’s, so I made tentative plans to head north and spend the day in the old growth forests of Mt Hood’s backcountry with Ron. Telemetry showed 2 inches of fresh snow when I went to bed at 10:00 pm, but 16 inches was on the ground by 5:00 am in the morning when I woke. As part of my normal routine, I checked the NWAC report, and the avalanche danger was rated Considerable. After exchanging texts with Ron, we agreed it was a go and I hit the road heading north on I-5, arriving at his place around 7:00 am. We arrived in the parking lot around 8:15 am, with low visibility, moderate winds and moderate snowfall. It looked like about 18 inches of new snow had fallen overnight, and by 8:30 am we had packs shouldered and were on the skin track.

The temperature was hovering around 20 degrees, and though the snow was light, the winds had created wind slab in places. Touring out towards Sand Canyon, we noticed some compression cracks while skinning. Due to the conditions, we were quite cautious when crossing Sand Canyon, performing a couple of hasty pits and other tests. Results indicated the slab was reactive, but no bed layer was present. Continuing on, we came to the PCT crossing of the Little Zigzag Canyon near 5800 feet, the only point on our tour that posed any real objective danger. The west face of the Little Zigzag was the windward side, but still we were cautious on the descent. Even though the canyon walls are only about 100 feet high, they have potential to be dangerous in the right conditions. We skied down one at a time, and regrouped in a safe spot near the bottom of the canyon to discuss heading up the opposite side. Ron agreed to proceed cautiously, with the intention of performing another hasty pit when he was partway up the canyon wall and a few hundred feet from me. I waited as he set out, and snapped a picture of him heading out on his way (below). Shortly after, I put the camera away to focus solely on watching him.

About 10 seconds after I put my camera in the bag, I saw a shooting crack run out in front of Ron and heard him yell Slide! I watched as the slope shattered like glass and started to run down around him. At first, I thought it was small enough to just run by him, but the entire slope failed and came down. Even though it’s only 100 feet, it packed a mighty big punch and knocked him off his feet. In fact, the toe of the avalanche came down towards me and ran a few feet past me. I watched Ron move downhill slowly, and he appeared to slide about 30 feet before a second wave of snow covered him up. What happened next was a bit of a blur, but I remember seeing a hand wave once, and then it was gone. My initial thoughts were “shit, this is actually happening” and “how could he be buried on such a small slope.” I remember feeling a bit panicked and started moving towards where I’d last seen his hand, then stopped and regained my composure. Years of avy training in courses and on ski patrol took over, and I pulled out my beacon, got a signal and found him within what I estimate to be about 90 seconds. He was fully buried, with only half of one arm out and a portion of his face exposed. Later I learned his mouth had some snow in it, but he could breathe through his nose. Given he’d only traveled 25-30 feet, he was uninjured and I was able to dig him out in about 5 minutes. The next hour was spent digging for his ski poles, which we eventually found a few feet below the surface. The below picture shows the debris pile looking up the east facing canyon wall.

After we found Ron’s poles and regained our composure, we explored the bed surface of the slide and found a sun crust (which wasn’t present on the very similar and same aspect slope in Sand Canyon). The crust produced a quality one shear. The weak layer was the very light low density snow that has fallen as the storm cycle began, and the obvious slab was the wind slab created from the recent new snow and wind. In the hour or so that we looked for Ron’s poles, we had significant time to reflect on what happened, what we could have done differently, etc. There were a couple of key take aways from this event for both of us. First, there were obvious signs of instability, and we were aware of them. Skiing in the storm cycle is something many people (including me) do routinely and something that can be done safely. The difference from this tour is that normally the zones we ski on higher avy days can be reached without encountering any objective hazards. On this tour, the Little Zigzag is basically the one objective hazard between the car and the safe skiing zones, and it is a very small feature on Mt Hood. This is take away number one, and something I’ve known but obviously didn’t give enough credence too on this day – small slopes (and even really small slopes) can be dangerous in the right conditions and can ruin your day. They should be treated with the respect they deserve, and one should be especially cautious of them during high avy days as it’s easy to let your guard down and think that if they slide nothing will really happen.

Takeaway number two – if possible, completely eliminate the objective hazard. In this case, we likely could have crossed the canyon several hundred feet down the slope, which would have been prudent. And, of course, there’s always the option of turning around if a safe crossing doesn’t exist. My last take away relates to alpha angle and runout. Even though I felt I was in a safe spot if something were to happen, the toe of the avalanche ran past me by a couple of feet. In retrospect, the next time I’m out, I’ll be applying a larger safety factor to potential runout zones when skiing one at a time.

After our incident, and a discussion on what lay ahead, we made the decision to continue on rather than head back to the car, given the rest of the tour to get to our objective consisted of skinning through low angle glades. Around 11:30 am, we reached a suitable place to head downhill and peeled skins, making turns down through the nicely spaced old growth. The wind affected snow near treeline gave way to very nice powder protected by the shelter provided from the trees. The first run was good, but we skied a bit tentatively, wanting to make sure the conditions were bombproof, which they proved to be.

We skinned back up for another lap, and this time opened things up a bit, skiing the whole line from top to bottom, confident what to expect after our first lap. Ron snapped a few photos of me, and I returned the favor and pulled out my camera and fired off a few shots…

We utilized our existing up track and ended up making another three laps, each one as good as the last in the fresh snow. It continued to snow the entire time we were touring (the forecast had only called for less than an inch during the day), with and additional 5-6 inches falling since our morning incident. Around 2:30 pm, we decided it was time to head back to the car, knowing we still had to recross the Little Ziggy. Our skin track from the morning was completely filled in, so another 3 miles of trail breaking was the price we had to pay. Coming back to the Little Zigzag, we were extra cautious prior to crossing. Skiing downhill of the fracture line (to a point where the slope didn’t release) we performed extensive tests trying to get the slope to release – it didn’t. Skiing back up hill to our earlier crossing from the morning, we dropped in one at a time, skiing the bed surface, which had 5-6 inches of new snow on it. Ron went first, and I followed when he was over to the opposing canyon wall. The remainder of the skin out was uneventful, and soon we were back at the car, tired after a long, fun and lesson filled day.

The car ride back to Ron’s was filled with discussion about the day, and mostly continued discussion about our incident. At Ron’s, a cold IPA hit the spot before I embarked on the two hour drive home. Cruising down I-5, I was thankful for another day in the mountains and for the lessons learned from this day. Below is a parting shot of Ron skiing the trees.