Yatsugatake (八ヶ岳) winter ridge hike

Mountain range:  Yatsugatake (八ヶ岳)

Map sheet: 33 [Yama-to-kougen-chizu (山と高原地図) series]


The Akadake-kōsen area of Mt Yatsugatake is deservedly famous for its topography, dramatic views and a whole host of classic winter alpine and ice climbs. Viewed from near the Akadake-kōsen hut, the face tumbles down like a bar code; black and white... ridges, buttresses, gullies and frozen icefalls. It is a true winter playground.

Framing it all are 3 of Yatsugatake's highest peaks; Akadake (赤岳 2899m) and Iodake (硫黄岳 2760m) mark the southern and northern ends respectively, with Yokodake (横岳 2760m) propping up the middle. A winter traverse of the jagged ridgeline connecting these 3 peaks is one of the classic winter hikes in Japan.

The area can be reached by a gentle 2.5-hour walk up the trail from Minotoguchi (美濃戸口).

The Daidoushin and Kodoushin rock outcrops:

The Akadake-kōsen hut:

Akadake seen from the hut:

If you are planning to head back down to Minotoguchi and out to the Chuō Line the same day then you'd better get an early start, around 5am or earlier.

From the Akadake-kōsen hut turn right out of the door and head in the direction of Akadake. After about 20 minutes the path will ascend a fairly gentle slope for a while, with zig-zags, crest a small ridgeline, and descend down the other side. After about 30-40 minutes of walking you'll arrive at the Gyoja-goya (行者小屋) hut at the top of Minami-sawa (南沢). From here the path forks off left up the Jizō-one ridge (地蔵尾根) to a col north of Akadake on the summit ridgeline. This path is a straightforward approach to Akadake, but a more aesthetically pleasing hike is to traverse the peak, so keep going straight on to the Bunzaburo ridge (文三郎尾根). The path forks once more, with the right fork heading towards Amidadake (阿弥陀岳), but you need to stick to the left.

Looking across to Amidadake:

Things begin to steepen here, and the wind might be fairly strong from the southern hon-dani side of the mountain, but it is never steep enough to have to front point. Once you crest the connecting ridge between Akadake and Amidadake, the path heads round the side of Akadake, out of view from below. Follow it up here, with chains in places. You will see some stunning wind-blown ice formations in this area.

You will soon reach the summit of Akadake. Take your summit shots, thank the Gods of the summit shrine for your safe passage, and head over to the summit hut (closed in winter) to begin the descent.

Summit marker:

Akadake summit shrine:

The view south to Gongendake and Asahidake:

The hut on the summit of Akadake:

Mt Fuji:

After about 20 minutes of careful walking down the northern flank of Akadake you will reach the top of the Jizō-one ridge (marked by a stone Jizō statue). From here continue on and up, with chains in places.

The next hour is the most exposed part of the day's hike, so be careful. There is one section that requires particular care, involving a traverse of around 30m across an open area at the top of several of the climbing routes; a slip from here would be serious.

Looking back on an easy section:

Looking back to Akadake:

Eventually you will reach the summit of Yokodake, and be rewarded with an incredible view back along the ridgeline to Akadake, with Mt Fuji (富士山) off in the distance:

Yokodake summit:

Continuing down the other side of Yokodake be careful getting down to the short ladder; in certain conditions it will require an exposed 5m downclimb facing into the ridge on steep and unprotected snow, but it is over quickly. After the ladder, a dramatic descent down the narrow ridge with chains brings you to a point where the slope eases, the ridge opens out, and the day's exposure has ended. From here, continue walking along to the hut below Iodake, and then ascend the line of cairns to the summit.

Iodake:

Iodake summit:

From the top of Iodake, walk down the ridge to the southwest, where you will meet a signpost showing the way to the Akadake-kōsen hut. After an initial short and steep snow slope (be careful, 2 climbers died here in an avalanche), the path enters the treeline. Follow it down for about an hour and you will return to the day's starting point at the hut. From here, you just need to wander back down the trail to Minotoguchi and civilisation in the warm glow of a perfect day.



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