U.L. SLEEPING SETUP
I dozed off shortly after dinner, sometime past 8 p.m. In general I'm a cold sleeper, so I went into the evening expecting it to be a long, uncomfortable night with the minimal sleeping setup I had brought to test out on this trip. One of the tricks I often employ to get or keep warm on winter evenings is to boil a pot of water, pour it into my Nalgene bottle and bring it with me into my sleeping bag to act as a heating pack. That was how I planned to start the night, but I fell asleep before I had the chance to follow through.
The skies had cleared by early evening, so we knew to expect a precipitous drop in temperatures after dark. A quick check of the temperature gauge upon awaking at 6 a.m. showed a reading of -6C/21F inside the emergency hut. It was likely minus double-digit temps outside our hut, which was perched just at the edge of the tree-line just above 2,000 m. Those were still not extreme numbers compared to how low the temperature can and often does drop in mid-winter in Japan, but it was cold enough to push my gear to its limits.
This last summer I spent numerous nights in the mountains camped above 2,000 m using only a 1 cm thick ultralight foam sleeping pad and a paper thin "SOL Escape Lite" bivvy - basically an emergency blanket sewn into the shape of a sleeping bag. I was frequently chilly, but slept better than I would have expected, and since then I had often thought of trying to save space and weight in my pack by taking a different approach to my winter sleeping system as well. Yet until this trip, the curiosity to test out something was easily outweighed by the fear of possibly freezing to death in my sleep. However, when doing a bit of research prior to packing for this trip, I stumbled across a handy chart that seemed to offer enough reassurance that I might be able to survive after all. ;)
According to this information, I should be able to stack my 0C/32F rated 3-season Mountain Hardwear Phantom sleeping bag and my 13C/55F rated MontBell Alpine Burrow Bag #7 summer sleeping bag to roughly equal the same warmth as a single -12C/10F winter bag. The idea made sense, and I had heard anecdotes of people utilizing this trick for years, but I had never seen numerical "proof". Now with the numbers on paper easing my mind, I made the decision to give it a shot. But staying warm in winter is also heavily dependent on how well you insulate yourself from the ground.
Most standardly quoted literature recommends a sleeping pad with an insulation (R) value of at least 5 for winter camping. But those pads tend to be bulky and heavy. I wondered if I couldn't cut more size and weight by taking the same approach, and double up on two summer pads. This time, with no fancy chart or empirical data to guide or reassure my decision, I decided on a whim to give it a try. I packed my old 1/2 length MontBell ultralight inlfatable pad, and the same 1cm thick barebones foam pad I used throughout the summer and called it good, but not before giving it a quick test on my porch for a few hours in temps that were hovering right around freezing. In the end I probably saved 15L of bulk and at least a kilogram and a half of weight.
To finally get to the point, the results exceeded my expectations. I woke up 2 or 3 times during the course of the evening mildly but manageably cold, and warm enough to quickly fall back to sleep each time. In fact, I probably slept better than I have in a long time, even when I was using my heavy, bulky and expensive winter equipment.
TO THE RIDGE
Zawa-san and I had a hard time getting out of bed, but finally managed to do so around 6 a.m. Because of more uncertainty with the weather in the form of forecasted heavy winds during the day and more snowfall on the following day, we had already decided to give up on the trip to the summit of Mt. Yakushi, but we still wanted to try and salvage A summit. The obvious, most immediate way to do that was to climb the slope directly above our hut to the summit ridge and across to the nearby peak of Mt. Kita-no-Mata. Since we would be returning to the emergency hut, we had the luxury of bring only essential gear with us on the climb, consisting of an extra insulating layer, helmet, goggles, ice axe, crampons, shovel, beacon, probe, snacks and water.
The area between us and our goal was a broad, treeless, undulating slope that wouldn't be particularly intimidating in most situations, but in the back of both of our minds were the eerie sounds of the unstable snowpack collapsing below our feet the day before. The overall slope gradient was below what is considered to be the danger range for avalanche occurrence, but there were certainly sections here and there that climbed above the 30-degree mark and crossed into potentially dangerous territory. I was very upfront with Zawa-san, and told him that if we heard or saw anything that indicated unsafe conditions, we would need to turn back, to which he agreed.
We had an opportunity to test the snow on some low-angle stuff immediately adjacent to the hut before we began to climb. Everything seemed ok, but we were still on edge with every sense ultra-tuned to our surroundings. Any area that seemed the least bit sketchy, we implemented a one-at-a-time rule so that if something did happen, on of us would be able to help the other. Instead of taking a direct line up as you likely would in summer, we zig-zagged our way up the slope slowly, reading the terrain and opting for the lowest-angle and/or or most protected route. Snow conditions luckily seemed more stable as we climbed, but the wind, conversely, steadily intensified to the point that it became hard to walk straight against the biggest gusts.
Despite all this we were moving much faster than the previous day, even with the need to tread through soft, deep snow once again across the initial portion of the climb. The views of Mt. Yakushi improved with each step up the mountain until we both found ourselves tingeing with regret at being unable to check its seductive snowy summit off our to-do list for the day. But luckily those feelings were countered by the battering bursts of wind that reminded us all too often we were making the right decision.
TO THE SUMMIT
Before long, we peaked over the last steep section of the icy windswept slopes and spilled out onto the well-defined summit ridge that stretched unbroken for what seemed to be forever. To the left was Mt. Yakushi, and to our immediate right was Mt. Kita-no-Mata, with Mt. Kurobegoro tantalizingly close beyond. Here the views and the winds were at their peak. The snowcapped Northern Alps in all their glory stretched marvelously before us, but brutal winds beat back most of the attempts, and frankly the desire, to try and photograph or film them. Here the wind was likely blowing steadily above 20 m/s (45 mph), with gusts up to 25 m/s (56 mph).
The summit plateau was broad and forgiving, so we weren't in danger of being blown off, but in order to move forward we had to consciously lean our bodies into the wind. This does the trick when the air is moving at a constant rate, but throws you off balance when it comes in unpredictable bursts like it was on this day. I dropped to my knees several times to keep from being knocked over and shuffled as quickly as I could to the rock pile marking the summit, hoping that I could duck behind it for even the tiniest bit of shelter and relief. I needed to add a layer for warmth, and hoped to switch to a Gore-Tex Wind Stopper balaclava and a pair of ski goggles to try and save my poor face from taking any more of a beating from the micro-darts of snow being thrown in all directions.
We each snapped a few quick photos and videos despite the challenges posed by the wind, before quickly beginning our descent. We had planned on following the same route we took up, since we had specifically navigated our way there using what we felt was the safest terrain, but the relentless winds had completely wiped out both our footsteps and the patience necessary to scout our descent with equal care. Still, we made it back to the hut safely and (mostly) satisfied, and while having fun on the way.
BACK TO THE START
We now turned our attentions to repacking our gear and giving the emergency hut a thorough cleaning, and were able to do both in about an hour. From there all that was left was to retreat back to the start. There always seems to be more ups and downs on the descent than you remember from the climb, and this was no exception. We retraced our footsteps on the undulating ridge, gaining and losing elevation in bunches along the way. By now the temperatures had climbed and the sun was beating the snow into wet, heavy submission. It seemed almost harder to follow the trace we had created the day before, than to carve a new path through the slush.
We reached the trailhead within a few hours, and tried to suppress the feeling of relief this usually affords, since we knew we had the soul-sapping 7km of snowy road still left to go. It was every bit as un-fun as we expected. Particularly for me, as the winter boots I had waivered back and forth about whether to use or not, had stayed true to their reputation for discomfort. The big toe on my right foot was being squeezed from a combination of the frozen, ill-fitting boots and the additional compression of the snowshoe straps across my toes. From the emergency hut all the way down I was in a lot of pain. I knew my toenail had been destroyed, but I had to just grit my teeth and bear the 14km walk back to the car because there was no other option.
In the end I of course did it, but it was a real test of fortitude. And yet, as the cars came into view and the stop button on my Garmin was engaged, the fatigue and hardships of the journey seemed to drown under the rushing hormonal high delivered by another active adventure in the mountains with a friend, and without much thought or hesitation, I turned to Zawa and asked if he would join me for a revenge hike on Mt. Yakushi next month.
"Sure.", he replied.