Route Name: Nishikuro ridge (西黒尾根)
Mountain: Tanigawa-dake (谷川岳)
Map sheet: 16 [Yama-to-kougen-chizu (山と高原地図) series]
Time: 3-4 hours to the top
Mt Tanigawa (谷川岳) sits along the prefectural border between Gunma and Niigata, and as the moist winter air from the Sea of Japan meets its summit ridge it lets loose colossal amounts of snow. The cornice that forms along that summit ridge can be the size of a house, and the area is renowned for avalanches when temperatures rise towards zero.
Tanigawa is home to some of the most demanding winter alpine climbs in Japan, many of which require serious skills, judgement and courage. For those looking to step up from the easier hiking trail at the southern end of the ridgeline, the Nishikuro ridge (西黒尾根) is an excellent way to reach the summit and sample the way conditions can be on Tanigawa, but with more moderate difficulty. In good consolidated snow it is quite straight-forward, dramatic at times but with little technical difficulty. In the darkest depths of winter though, you should be prepared for deep untracked snow and a level of adventure that belies its modest technicality.
From Tokyo take the Takasaki Line to Takasaki (高崎, about 1.5hrs). Change for the Jōetsu Line to Minakami (水上, about 45mins), then take a local for 2 stops to Doai (土合). From the underground platform at Doai station, climb a 489-step staircase from hell to reach ground level.
Exit the station and join the main road, turning right and walking under a railway bridge. Follow this road for about 20 minutes up to the Visitors Centre.
From the Visitors Centre you need to walk up the road to the mountain rescue hut and then continue on for two more switchbacks, and you will soon reach the trailhead for the Nishikuro ridge.
The first 10-15 minutes past the trailhead take you up a fairly steep forested trail until you crest the ridge below a large electricity pylon. Continue past this pylon up the tree-covered ridgeline for several hundred metres. Depending on the year or the stage of winter you’re hiking in, this section may well require snowshoes to make any progress at all. Eventually you’ll come to a short descent down to a level section with a striking cornice on climber’s left.
Continue upwards as the ridge begins to narrow and the trees start to thin out, and you’ll come to a sort of saddle at treeline. From here on you’re on the upper ridge, and things will become more interesting and more exposed.
First you need to traverse a few pinnacles, and a couple of minor rock steps with in-situ chains provide some added interest on this section. The ridge gets quite narrow in places, with mounting exposure on both sides and a large cornice on your left.
Looking back at the corniced ridgeline:
Beyond those pinnacles things broaden a little more, but the angle of the slope increases as you begin the ascent of a long snow slope past some rocks. The trace will most likely bypass these rocks to climber’s right, but taking them directly provides an enjoyable little scramble.
Now you’re really getting into the final steep upper section of the Nishikuro ridge so just keep going upwards, but once again, be very aware of the cornice on your left.
Eventually things will begin to level off for a short while, and then you’ll pop out onto the main summit ridge in front of a large cairn with signposts, just 50m horizontally from the hut. This cairn marks a trail junction, with the left route heading down the more gentle ordinary hiking trail to the Tenjindaira (天神平) ski piste, and the right route heading up to the summit.
Turn right and continue upwards, and you’ll soon arrive at the 1963m summit of Tomanomimi (トマの耳). This is as far as most hikers go, and on a good day the views are pretty special.
If you want to reach the true 1977m highpoint of Mt Tanigawa you’ll need to continue along the ridge for another 15 minutes to the top of Okinomimi (オキの耳). It really is worth the extra effort to get there, and the view back along the ridge to Tomanomimi is the classic money shot for winter hikers on Tanigawa.
Looking across to Ichinokura-dake:
There are three options for getting down, as follows:
(i) Continue along the ridge to the summit of Ichinokura-dake (一ノ倉岳), and then swing towards the west to Shigekura-dake (茂倉岳) and hike all the way down to Tsuchitaru (土樽) station. Be aware that very few people do this, so beyond Ichinokura-dake you’ll almost certainly be breaking trail through deep snow.
(ii) Head back over Tomanomimi to the sign-posted trail junction near the hut, and continue straight on down the ordinary path to Tenjindaira (天神平), and take the ski gondola back down to the Visitors Centre.
(iii) Descend the way you came up, straight back down the Nishikuro ridge. If your aim is to train for winter mountaineering then this is the recommended descent, as it will require you to negotiate your way down some steep and exposed snow slopes in the upper half, and will put an important 1000m of descent into your quads.
An excellent winter hike to one of the most fabled and exciting summits in the area, elegantly bridging the difficulty gap between the easier hiking trail from the ski gondola and the more serious winter alpine routes in Ichinokura-sawa and Yuno-sawa to the north. I’d recommend carrying snowshoes, even if you end up not using them. Treat this route as an opportunity to train for harder things, as well as an excellent winter ridge hike in its own right.