Route Name: Minamisawa-Ōtaki (南沢大滝)
Mountain: Yatsugatake (八ヶ岳)
Map sheet: 32 [Yama-to-kougen-chizu (山と高原地図) series]
Time: 2 hours for the approach
If you’re looking for ice to climb with a short approach walk, or you only have a day available, the Ōtaki (大滝) and Kotaki (小滝) in Yatsugatake’s Minamisawa (南沢) will fit the bill nicely. Be warned though that the convenient approach will probably mean you’ll be sharing the ice with a lot of other climbers on weekends.
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 Amidadake and the Akadake-kōsen side of Yatsugatake.
It takes about 2 hours to walk to the Minamisawa-Ōtaki, with about 700m of elevation gain. From the carpark start hiking up the trail that is signposted to Akadake (赤岳). 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 left fork going up Kitasawa (北沢) to the Akadake-kōsen, and the right fork going up Minamisawa (南沢) to the Gyouja-goya hut (行者小屋). You need to take the right fork.
Follow the trail as it meanders back and forth across the river, eventually steepening a bit and gaining height. After about an hour you will come to a fork. The trail continues to the left up Minamisawa, and the icefalls of the Ōtaki and Kotaki lie a few minutes up the roped off trail on the right.
A couple of minutes above the rope barrier you’ll come to another fork in the trail. There is flat space here for several tents. Just round the corner on the right lies the Kotaki, or little waterfall. It is about 15m high, with multiple fixed anchors on a line of trees set back from the top. A single rope will be enough to climb, rappel or set up a top-rope.
The main event, the Ōtaki, lies about 5-10 minutes up the left fork. It is about 45m high from the bottom to the anchors. There is no way to bypass it, so to climb it and get down safely you’ll need double ropes. The Ōtaki is mostly vertical, and the difficulty is around WI4 in bulletproof mid-winter deep freeze conditions. It is quite wide, so multiple parties can climb on it at the same time.
It gets cold on Yatsu in mid-winter:
A good day’s climbing on ice that is both higher and more vertical than the ice in Jougasawa (ジヨウゴ沢) or the Uradoushin-runze (裏同心ルンゼ), with a nice short approach walk.