Route Name: Ojou-heki (凹状壁)
Mountain: Tanigawadake (谷川岳)
Map sheet: 16 [Yama-to-kougen-chizu (山と高原地図) series]
Length: 8 pitches (295m)
Time: 4-6 hours to the top of the last pitch
Grade: V- crux pitch / Overall grade 4- alpine route
Situated on the right side of the Eboshi-sawa Oku-heki (烏帽子沢奥壁) in the Ichinokura-sawa (一ノ倉沢) valley, the Ojou-heki route ascends a wide and deep depression between the Chuo Kante and the Chuo-ryō, which gives the route its name. Its first ascent was in fact a winter ascent, in March of 1958. In summer conditions it is characterised by its somewhat loose rock and run-out nature, but the dramatic exposure and the dark brooding ambience of the Ojou make this a 3-star classic.
From Tokyo take the Takasaki Line to Takasaki (about 1.5hrs). Change for the Jōetsu Line to Minakami (about 45mins), then take a local for 2 stops to Doai. 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.
Walk up the road from the Visitors Centre for about half an hour until you get to the entrance to Ichinokura-sawa (一ノ倉沢). Head up the sawa until you reach the bottom of Tail ridge, and ascend this all the way to the top, at the foot of the Tsuitate-iwa (衝立岩) rock face.
From here make a short but exposed rising traverse to your left across the steep slabs in the direction of the Nan-ryō terrace. The Ojou-heki route shares its start with the Chuo-Kante, and you will quickly reach the bottom anchor (2 bolts).
As always on Tanigawa, but particularly on this route, you’ll need to channel your inner alpinist to avoid knocking any of the many loose rocks down onto people below you. Approximate pitch descriptions for the route are as follows:
Pitch 1: Traverse right from the anchor for 10m round the corner. Ascend another 20m on loose grassy rock. (30m III+)
Pitch 2: Climb up moderate terrain to a 2-bolt anchor. (40m III)
Pitch 3: Trend to the right towards the Ojou (凹状), and climb to a belay at the bottom of the vertical back wall above. (40m III+)
Pitch 4: Very loose balance climbing up a vertical chimney. Take care with every hold. (40m V-)
Pitch 5: Climb up and right on loose rock to a short bulging wall, then scramble up to a ledge belay. (35m IV)
Pitch 6: Up and to the right via some tricky moves then continue up the edge. (40m IV+)
Pitch 7: Climb overgrown grassy rock to belay on pitons beneath a steep flake. (30m III)
Pitch 8: Make steep and positive moves up the flake, then continue up to crest the top of Tsuitate-iwa. (40m IV+)
From the top of the Tsuitate-iwa you will need to make a traverse of about a rope-length to get to the top of the Chuo-ryō route, which will be the line of your rappel descent. It’s straight-forward but exposed, so it’s best to keep the rope on and pitch it.
From the anchor at the top of the Chuo-ryō make about 6 rappels on double ropes to get back down to the top of Tail ridge. Be really careful not to dislodge any rocks, in case there are parties still climbing on the Chuo-ryō.
From there you just need to scramble back down Tail ridge, then hike down Ichinokura-sawa to the road and walk back to the Visitors Centre.