【Deep Dive Chronicle】Kashiasahi-dake Winter Ridge: Late Winter Snow Traverse in Fukushima

Part I – Into the White World

On a March morning still heavy with winter’s presence, we departed from Kasshi Onsen. The temperature was low, the snow lightly compacted. A thin layer of fresh snow from the previous night blanketed the ground with a soft touch underfoot. The sky was blue, the air still. We could not have asked for better mountaineering conditions.

Our destination, the Kasshi Mountain Range, sat with quiet dignity in a remote corner of the Oku-Nasu region. While Kasshi-yama, the first peak we would cross, is known for its expansive views, our true objective lay beyond: Kashiasahi-dake. Also called Akakuzure-yama (Red Collapse Mountain), this formidable peak exposes a severe snow face during the lingering snow season, demanding technical skill and unwavering resolve.

The ascent through the forest zone began gently, but as we reached the ridge, the snow surface gradually hardened. Branches illuminated by sunlight glowed white, and only our footfalls and breathing disturbed the quiet woods. Looking back, the Nasu Mountains shimmered in the distance under the morning sun.

Our party numbered twelve. Three members advanced on backcountry skis, while the rest proceeded on snowshoes and crampons. S led the way, cutting a steady rhythm into the snow, and I followed his tracks while listening to the sound of my own footsteps. It was a quiet time, like conversing with the snow itself.

Upon reaching Kasshi-yama, the white ridge of Asahi-dake rose before us. Against a cloudless blue sky, the sharp peak stood out, with faint winds racing across its white spine. The path to that summit would not be easy. Yet despite this knowledge, my heart beat quietly with anticipation.

Part II – Avalanche and Ridge

The ascent toward Asahi-dake was complicated by the previous day’s fresh snow. On slopes sheltered from wind, soft snow accumulated, and with each step we sank to our knees. The ski group and walking group maintained some distance from each other, each advancing at their own pace. We carefully observed the snow surface conditions as we gained elevation.

Then the snow moved. “It’s sliding!” The cry carried on the wind. K’s figure vanished momentarily into the white slope. A surface avalanche. Snow spray rose, the air trembled. Immediately, everyone froze, watching the slope. A wide fracture line had split the snow surface, approximately fifty centimeters deep. The detached surface layer gleamed dully in the sunlight where it had peeled away.

Fortunately, K managed to pull himself out of the snow. His equipment was undamaged, and he showed no signs of injury. But the atmosphere had changed completely. We had been shown, viscerally, the hidden power lurking beneath the snow.

The ski group decided to retreat for safety. The remaining walking group shifted our route away from the avalanche slope and onto the ridgeline. The ridge was sharp, dropping steeply on both sides. We placed our crampon front-points on a snow ridge barely wider than a single footstep, using ice axes for balance. The wind-hardened snow reflected the light blindingly. I could almost hear the sound of my breath freezing white in the air.

Occasionally, I glanced back at those following. Red jackets emerged vividly in the sunlight, their shadows stretching long across the snow surface, swaying in the wind’s current. I simply walked in silence through the space between wind and snow.

Part III – Summit Silence

We reached the summit of Asahi-dake past noon. The wind was light, sunlight illuminating the snow surface. Beyond Kasshi-yama, white ridgelines stretched one after another into the distance, with the mountains of Nasu hazily blue on the horizon. The snow surface was firmly compacted, producing a dry sound with each step.

We took our lunch there. The aroma of steaming instant noodles dissolved into the cold air. No one spoke much. The moment of the avalanche still lingered in our minds. Yet everyone’s faces showed relief. On a winter mountain, we were reminded once more of what it means to stand here alive.

The descent proceeded with caution. The ridge’s shadow stretched long, afternoon light slanting across the snow surface. We sensed the wind strengthening and traced the ridge at a quick pace. Upon entering the tree zone, the snow softened and tension gradually released. The sky remained blue, the sun declining.

Looking back, the white peak of Asahi-dake was染まっていた dyed in evening light. The end of a quiet day. Only the memory of crossing that knife-edge ridge remains, glowing coldly in the depths of my heart.

A sharp snow ridge, quiet sunlight, and a moment of avalanche. Kashiasahi-dake showed us equally the harshness and beauty that winter mountains possess. Under the clear March sky, we had indeed set foot on the white peak standing at winter’s end.

北村智明

登山ガイド

日本山岳ガイド協会認定登山ガイドステージ2。ガイド歴10年。東北マウンテンガイドネットワーク及び社会人山岳会に所属し、東北を拠点に全国の山域でガイド活動を展開。沢登り、アルパインクライミング、山岳スキー、アイスクライミング、フリークライミングと幅広い山行スタイルに対応。「稜線ディープダイブ」では、山行の記憶を物語として紡ぎ、技術と装備の選択を語る。