Route name: Kodoushin Crack (小同心クラック)
Mountain: Yokodake (横岳), Yatsugatake (八ヶ岳) range
Map sheet: 32 [Yama-to-kougen-chizu (山と高原地図) series]
Time: 3-4 hours
Difficulty: Grade 2 alpine route / IV crux
The Kodoushin pinnacle (a.k.a Shodoushin) may be the little brother of the Daidoushin pinnacle, but it is no less striking. Perched high on the west face of Yokodake above the Akadake-kousen, it is hard to imagine an alpine climber staring up at it from the hut and not impulsively wishing to stand on top of it.
By dint of good fortune, a striking natural chimney cleaves the front of this conglomerate pinnacle from bottom to top, providing about 100m of vertical climbing. It can be done year-round, but to extract the full experience from it you really need to go there in the winter season, when the rock is frozen in place and gloves, boots and crampons are a necessity.
To satisfy your inner alpinist, continue on behind the pinnacle where a final mixed pitch leads directly onto the 2829m summit of Yokodake, making this one of the most aesthetic days of climbing to be had in the Yatsugatake massif.
If travelling from Tokyo, take a Super Azusa Limited Express train from Shinjuku to Chino (approx. 2.5 hours). Outside the JR station at Chino take a bus to Minotoguchi (美濃戸口, approx. 45 minutes). This is the gateway to the Akadake-kōsen side of Yatsugatake. From the car park start hiking up the trail that is signposted to Akadake (赤岳).
The walk-in takes up to 3 hours by map time. It is split into 3 stages. The first hour brings you past a series of buildings and on a little further to a hut with a water source, which makes a good resting point for 5 minutes.
The trail splits here, with the right fork going up Minami-sawa (南沢) to the Gyouja-goya hut (行者小屋). You need to take the left fork up Kita-sawa (北沢). The next hour follows the rough dirt road until it finishes at a bridge across the sawa. From the other side the path narrows and meanders alongside the sawa for another hour or so until you reach the hut at Akadake-kōsen. This hut and its campground serve as basecamp for all the routes in the area.
From the Akadake-kōsen hut go up the steps near the door and take the path straight on towards the ice routes (Daidoushin runze, Uradoushin runze, Jougosawa) on the left-hand side of the face below the summit of Yokodake (横岳). Follow the trail for about 5-10 minutes through the forest and you will come to a signpost pointing right into the bottom of the Daidoushin runze (大同心ルンゼ), or gully.
Head into the Daidoushin runze and follow the stream for about 10 minutes and you will come to a trail heading up on your left along the lower section of the Daidoushin-ryo. Follow this up through the forested ridgeline.
The trail is gentle at first, getting steeper as it progresses, eventually exiting treeline and ascending several easy mixed steps to its apex at the foot of the Daidoushin rock pinnacle. From the top, traverse the descending ramp (大同心バンド) around the south side of the pinnacle until you reach the bottom.
Carefully cross the top of the Daidoushin-sawa on your right, and then climb the steep snow slope for around 100m until you reach a wide flat terrace at the foot of the Kodoushin pinnacle.
There is no fixed anchor here, but this terrace marks the start of the first pitch of the Kodoushin crack.
Approximate pitch descriptions are as follows:
Pitch 1: From the terrace climb up the face and trend left to gain entry to the chimney crack at about 15m height. Continue steeply up the crack through several bulges to reach a bolted belay anchor. (40m IV-)
Pitch 2: Continue straight up the chimney crack, through several bulges, until you reach a comfortable bolted belay terrace. (30m IV)
Pitch 3: From the belay climb a steep crack on your right, then make an exposed traverse out to the left to gain the final few metres of steep rock that will bring you over the lip and out of the face. There is an anchor here if you wish to break the pitch, but you can equally continue on for 10m up easy ground to another anchor just below the top of the Kodoushin pinnacle. (25m III)
From this top anchor, scramble up several metres of easy terrain to gain the top of the Kodoushin. Now walk along the narrow ridge that joins the Kodoushin to the Yokodake face, then ascend easy ground to belay on bolts at the foot of the final rock face directly below the summit of Yokodake.
Looking up to the summit of Yokodake:
One final 30m mixed pitch of grade III (slightly run-out, but with good crack placements for small cams) will bring you onto the flat summit of Yokodake. On a clear day the views up here are second to none and extend for well over 100km in all directions!
The quickest way down from the top of Yokodake will be to head north off the summit down the hiking trail (in-situ chains on the steep sections) to the col on the ridge above the Daidoushin pinnacle. Carefully descend the steep slope on climber’s left towards the Daidoushin, and scramble down to a rappel anchor at the top of the final chimney of the Daidoushin-runze.
Make a short rappel down this on one rope, and you will find a solid bolted rappel anchor on the wall just around the corner on climber’s right. From this anchor a 60m rappel on double ropes will get you down to the bottom of the gully.
From here simply reverse the way you came in, initially along the traverse ramp below the Daidoushin, and then back down the Daidoushin-ryo descent ridge to the entrance of the Daidoushin-runze and on back to the hut.
If logical lines up stunning natural features are important to alpine climbers, then this route should be high on the list of all Yatsugatake winter alpinists. They really don’t come much better! Bring 60m double ropes, around 12 quickdraws and slings, and a couple of small cams.
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