Mt. Upepesanke-yama (ウペペサンケ山, Upepesanke-yama) is named after the Ainu name upepe-sanke- nupuri, meaning ‘mountain that pushes out snowmelt’—an account backed up by late-Edo Period explorer Matsuura Takeshiro (松浦武四郎) in his Records of the Tokachi (十勝日誌, Tokachi Nisshi). The mountain is the headwaters of both the Otofuke-gawa River (音更川, Otofuke-gawa) and the Shikaribetsu-gawa River (然別川, Shikaribetsu-gawa). The huge trapezoidal mountain is usually paired with Mt. Nipesotsu-yama (ニペソツ山, Nipesotsu-yama), its brother in the Eastern Daisetsuzan (大雪山). There are two trails up the mountain: one heading up from the lake side near Lake Nukabira-ko (糠平湖, Nukabira-ko), and one climbing up from the hot springs at Kanno Onsen (菅野 温泉). In this guide we’ll introduce the Nukabira Trail (糠平コース, Nukabira kosu).
At the intersection of National Route 203 (国道203号線, Kokudo 203 gosen)—which passes through Nukabira Lakeside Village (糠平湖畔, Nukabira-kohan)—and Prefectural Route 85 (道道85号線, Dodo 85 gosen), you’ll head towards Tokachi-mitsumata (十勝三股) district and shortly see a sign by a forest road heading up the Nukabira-gawa River (糠平川, Nukabira-gawa). At the end of this road you’ll find the trailhead.
The trailhead is already at 900 meters above sea level. From here the climb continues on foot through a dense forest. Just after setting off you’ll find a place where you can fill up on water; after this there will be no more watering holes on the trail.
Once you’ve climbed up to the 1399-meter peak at the top of a steep hill, you’ll suddenly be presented with wide open views. Past the small peak, the long walk along the ridge begins. A little ways further along, you’ll come the Kanno trail junction (菅野温泉コース合流点, Kanno Onsen kosu goryu-ten) where the trail joins from the left. Looking eastward from here you’ll see Lake Nukabira- ko itself and the cluster of lava domes that sit around it.
As you approach the 1834-meter Nukabira-fuji (糠平富士), you’ll traverse along a pleasant ridge covered in dwarf stone pine. Among the trunks of the pine you’ll also see Kamchatka rhododendron, bog-star, and lingonberry; little ravines and rivulets will wind down through the pines below you. From Nukabira-fuji you’ll be able to see the full length of the ridge ahead of you and the trapezoidal mass of Mt Upepesanke-yama itself.
You’ll drop into a col between summits and cross a rocky ridgeline before arriving at the summit of Mt. Upepesanke-yama. The summit is littered with alpine bearberry and bog bilberry; in fall, the contrast is beautiful between the red leaves and the dark green of the pines. Below, the dark deep forest of the Eastern Daisetsuzan will spread out like a carpet, watched over by the sharp peaks of Mt. Nipesotsu-yama across from you. To the left of Nipesotsu, you’ll see the tall cone of Mt. Maru- yama (丸山, Maru-yama); it probably doesn’t take a volcanologist to recognize the huge volcanic power of the Daisetsuzan at work here.
From here, if you continue the traverse westward, you can cross an unnamed 1836-meter peak and descend to Kanno Onsen. This route, called the West Ridge Trail (西尾根コース, Nishi-one kosu), is the shortest route to the summit. It starts at the end of a forest road and climbs up to a col west of Upepesanke itself; if you can sort out leaving a car at this forest road, the traverse from Lake Nukabira-ko to Kanno Onsen is a great trip.
From the summit, you’ll start the long walk back to where you started. As the windswept ridgeline can get quite difficult to travel in bad weather, it's a good idea to make your plans with a sufficient margin of error.
- You can catch a Tokachi Bus (十勝バス, Tokachi basu) from Obihiro (帯広) to Nukabira Onsen. The ride takes about 1 hour, 40 minutes. You can alternately take a taxi from Kamishihoro Town (上士幌町, Kamishihoro-cho).
- Nukabira Onsen’s baths are terrific; there are a good number of bathhouses you can use.
- The Eastern Daisetsu Museum (ひがし大雪博物館, Higashi-Daisetsu Hakubutsu-kan) is the authority on nature in this part of Hokkaido. Their insect exhibit is particularly comprehensive.
- The Kanno Onsen Trail starts at the end of a forest road following the Yuyanbetsu-gawa River (ユウヤンベツ川, Yuyanbetsu-gawa). You’ll start off following the stream, then climb up to a spur, where you’ll meet the main ridge of the mountain. From trailhead to the junction takes about 2 hours, 30 minutes. The West Ridge Trail (西尾根 コース, Nishi-one kosu) starts at the end of the Ishukari- gawa River (イシュカリ川, Ishukari-gawa) forest road, and takes about 3 hours to reach the summit of Upepesanke. The Ishukari-gawa forest road might be closed depending on the circumstances, so check before heading out.
In the early half of the season the pattern of the remaining snow against the bright green of the trees is brilliant. The flowers are at their peak from mid-July to August—you’ll see Kamchatka rhododendron, iwabukuro beardtongue, Alaskan arnica, and bog-star along the ridgeline. The leaves start changing from around mid-September. The yellow leaves of the mountainside Erman’s birch and the bright red of the alpine bearberry on the ridge make for a beautiful contrast.