Route Name: Kuro-sawa (黒沢)
Location: Matsuki-sawa valley (松木沢)
Map sheet: 13 [Yama-to-kougen-chizu (山と高原地図) series]
Time: 1 day
Grade: WI3+ / Overall grade 2 alpine route
Tucked in behind the Nikkō mountains, near the former copper mining village of Ashio, the Matsuki-sawa valley is a place of contrasts. This area was an important source of copper for the Japanese government from the Meiji era right up to the 1970s, when operations were ceased. It suffered many environmental disasters along the way, and the landscape at the head of the valley is still deeply and visibly scarred by this history.
Despite all this, once you enter Matsuki-sawa you will likely be struck by the beauty and ambience of the place, with its steep craggy cliffs and alpine feel. It’s an impressive place, and made even more beautiful by the absence of the hordes of hikers that are to be found in Japan’s more well-known mountainous areas. From hiking to sawanobori, multi-pitch rock-climbing to alpine ice-climbing, the area is an adventure playground and a real reward to those who make the effort to find it.
If travelling from Tokyo (東京) by car, take the Tōhoku Expressway as far as Utsunomiya (宇都宮), then change onto the Nikko-Utsunomiya road until it turns into Route 120. Turn left onto Route 122 and stay on this until it meets Route 250, then turn right onto Route 250. Keep going straight on up the Ashio (足尾) valley on this road until you reach its end at the small car park above the Akagane Water Park (銅親水公園).
From the car park, you need to walk a little further up the road you drove in on, go past the barrier blocking the road, and cross the bridge to get over the river on the left. Walk along the road as it doubles back round to the left and then swings northwest again towards the entrance to Matsuki-sawa (松木沢).
Once into Matsuki-sawa you need to keep walking for about 1.5 hours to reach the entrance to Kuro-sawa (黒沢). Initially you will be on a good dirt road until you reach the Matsuki village.
From there onwards the road becomes less maintained, and in several places has been completely covered in boulders from landslides and rockfall from the mountainside on your right. On the left side of the valley large rock faces begin to appear, and the summit ridge of Nakakura-yama (中倉山) can be seen high above. This ridgeline eventually leads over Koushin-san (庚申山) to Nokogiri-yama (鋸山) on the main ridge before the summit of Sukai-san (皇海山), and is a dramatic and high-quality hike in its own right.
Eventually you will arrive at a large concrete dam next to the Kuro-sawa valley coming down the mountainside on your left. You will be able to see the first few icefalls from here. Scramble down to the river and cross it by whatever means available, then hike up the approach trail on the other side.
The first icefall (F1) does not always form very well, and is rather gentle anyway, so this can be bypassed by sticking to the trail up on the right.
This trail will soon enter the sawa, and then several hundred metres of hiking up the frozen river will bring you to the main icefalls.
F2 is approximately 30m high, and can be tackled straight up the middle or close to the rocks on its left side. There is a bolt anchor at the top of it on the right. Many thanks to Mathieu for replacing the previous rusty old anchors with these solid bolts.
The F3 icefall is located directly above F2, and is the tallest fall along this route. There are plenty of ways this can be tackled. Most parties climb it in two pitches, an initial 40m pitch leading to an old bolt anchor on the rock above the centre of the icefall, then a shorter 10m pitch up the narrower section to the top, with a solid bolt anchor on the right. With 60m ropes you could climb it in a single direct pitch if you like.
After this you need to hike quite steeply for about 10 minutes up the sawa to reach F4, a 30m icefall in a sort of gorge-like constriction. There is a tree anchor just back from the top of this one.
To descend, just rappel the icefalls on good in-situ anchors and hike back down and out.
An excellent route in a beautiful location, with good quality icefalls of a satisfying length and a moderate difficulty. Recommended even as a one-day hit, it could also be combined with one of the neighbouring sawa routes to provide a very nice weekend of ice-climbing. February is the optimal month to find good ice conditions in here.