Kamui-dake (神威岳) is a mountain standing at the headwaters of the Motoura-gawa (元浦川) Naka-no-gawa (中ノ川) Rivers in south-central Hidaka (日高). Particularly from the Hidaka side of the mountains, the summit looks quite slender and steep; for that reason the local Ainu called it kamui, meaning ‘god’. Although the mountain isn’t particularly tall, the mountain’s name carries a certain solemn suitableness, especially in winter. In this guide we'll climb Nishuomanai-sawa (ニシュオマナイ沢) ravine route, but there are routes that climb the Ezomatsu-sawa (エゾマツ沢) and Naka-no-sawa (中ノ沢) ravines as well. Both of these are technical river climbs, however, so come prepared.
To get to the trailhead, you’ll follow National Route 235 (国道235号線, kokudou 235 gosen) out of Ogifushi (荻伏), pass through Kaminobuka (上野深), and turn onto a forest road following the Motoura-gawa River into the woods. The forest road is quite long, so rather than taking a taxi it’s a better idea to go by private vehicle or otherwise rent a car in nearby Urakawa Town (浦河町, Urakawa-chou). Once you’ve passed the place where the Ezomatsu-sawa River joins the Motoura, you’ll shortly come to the trailhead at Kamui Lodge(神威山荘, Kamui-sansou), a small hut where you can stay the night before the trek. As the first half of the trek involves climbing a ravine and the second half passes along a ridge, if you can prepare different footwear for river walking and ridge walking you’ll probably find the hike a little easier.
From Kamui Lodge you’ll cross the Nishuomanai-sawa Beck and follow its right bank along and old logging road. Soon you’ll hit a 'junction' at 440 meters above sea level (440メートル二股, 440-meetoru futamata). This isn't a junction in the traditional hiking sense (viz. where two trails meet), but rather where two valleys meet. Accordingly, it uses the Japanese words futamata, meaning 'a parting of the ways' rather than the usual bunki, which generally refers to a standard trail junction.
At the 440-meter junction you’ll cross a tributary and continue along the main ravine’s right bank. After making your way around a short waterfall, you’ll continue the climb up the stream itself. As there are no big falls, so long as the water level is about average the climb shouldn’t be too much trouble, even for someone who has never done any sawa-nobori (沢登, lit ‘stream-climbing’) before. Where the valley opens up you’ll be able to see the ridgeline above you.
At the 524-meter junction (524メートル二股, 524-meetoru futamata) you’ll take a left, past which the stream will start to peter out and the climb will start to get quite steep. In fall, the leaves around here are particularly beautiful. The ridgeline above is particularly representative of the look of Minami-Hidaka (南日高), the southern part of the range; it’s covered in huge Japanese white pine trees. The trail cuts right at the 710-meter junction (710メートル二股, 710-meetoru futamata) and climb up onto the ridge spur leading towards the summit. This is the last place you’ll be able to fill up on water along the trail.
From the lower spur up to the main ridge of the mountain will be a steep climb, gaining quick altitude. This sort of steep climb is a characteristic of Hidaka’s sharp ridges and peaks. You’ll pass through a mixed forest of pine and Sakhalin fir, followed shortly by a forest of the gnarled-looking Erman’s birch, thinning out as you climb.
You’ll emerge on the spine of the main ridge coming from the north and find yourself in a field of dwarf stone pine. Behind you, Mt. Betegari-dake (ベテガリ岳) will stand above waves of mountains stretching towards the horizon, making the last climb up to the summit of Kamui-dake a beautiful (if tough) endeavor.
The view from the summit is flawless. You’ll be able to spot the summits of Mt. Ezomatsu-dake (エゾマツ岳) and Pirikanupuri (ピリカヌプリ) over the deep valleys below; and on a clear day you should be able to see the dark shadow of Mt. Rakko-dake (楽古岳) in the distance. The ridgeline from the summit to neighboring Ezomatsu-dake is Hidaka’s narrowest trail--in Japanese it’s called ‘Kutsubaba Ridge’, or ‘Shoe’s-Width Ridge’.
You’ll head back down the way you came up. Looking out over Minami-Hidaka should be a welcome distraction as you descend.
Where the trail descends off the ridge and back into the valley, there is a small path that leads along the ridgeline northwards to Naka-no-dake (中ノ岳). Many hikers miss the turnoff here and wind up walking along the ridgeline for a while before realizing their mistake--take heed not to confuse the trails.
For the first half of the season the patterns that the melting snow makes in the ravines is particularly beautiful. In August you’ll be able to see some flowers on the mountain-- for example Ezo burnet and Japanese saxifrage grow plentifully. The changing leaves will be at their peak beauty in late September. But since the snow comes quite late here, the best time to visit the mountain is probably in late fall.