The name of Mt. Aka-dake (赤岳, Aka-dake) comes from the Aine ‘fure shuma pet’, meaning ‘red stone river’. It was thought that this mountain was the headwaters of the Akaishi-gawa River (赤石川, Akaishi-gawa, lit. ‘red stone river’), but when the area was explored further and the maps were corrected, the name stuck. The trail from Ginsen-dai (銀泉台, Ginsen-dai) to Mt. Hakuun-dake (白雲 岳, Hakuun-dake) offers a terrific taste of what the Daisetsuzan has to offer, both in richness and variety of flora—which makes it a very popular route for weekend hikers. Ginsen-dai sits at about 1500 meters above sea level, so in the fall you can see the changing leaves from the trailhead onwards.
Ginsen-dai sits at the end of a scenic road climbing into the mountains from Lake Daisetsu-ko (大 雪湖, Daisetsu-ko), a huge reservoir at the heart of the Daisetsuzan. It might surprise you to know that at one point a road was planned to cross the Daisetsuzan—it would have connected Ginsen-dai to Asahidake Onsen in the east. Due to public opposition, however, the plan was canceled.
From the end of the forest road you’ll start up a steep slope covered in Matsumura whitebeam and small bushes. On the upper part of this first climb you’ll making a wide right hand-turn, crossing two snowy valleys and gaining elevation on your way to the plateau of Komakusa-daira (駒草平) ahead.
After the snow thaws, in the grassy meadows along the trail here, flowers like Alaskan arnica, yellow-flowered rhododendron, and Aleutian mountainheath will be in bloom all summer. Past here, you’ll cross a small marsh, climb a short slope, and come to Komakusa-daira Plateau.
The komakusa bleeding-heart flowers of Komakusa-daira are disappearing, likely due to hikers picking them as they pass, or from hikers leaving the trail and stepping on them accidentally. Action is being taken to maintain the flowers’ populations, but while you’re here, make sure not to damage either the plants or the Eversmann’s Parnassian butterflies that feed on them. Alpine grasslands like this are delicate ecosystems.
Past Komakusa-daira, you’ll wind through dwarf stone pine and come to a third snowy valley. You’ll head up to your left, passing bright blue heath and Kuril saxifrage as you go. The trail gets a little wide here, so stick to the middle and don’t drift off into the brush. Mt. Aka-dake itself sits on the far side of yet a fourth valley ahead. Along the edges of the valley here you’ll probable see alpine azalea spreading out in a colorful blanket; but by the time you reach the ridgeline above it will have been replaced by stout pansy and mountain avens.
The summit of Mt. Aka-dake might boast the best views in the northern Daisetsuzan—and here you might have been thinking you’d seen enough of its charms on the climb up. From here you’ll head along a relatively even trail to the summit of Mt. Koizumi-dake (小泉岳, Koizumi-dake), so feel free to take your time and take in the views. On the windblown ridgeline, look for Japanese locoweed and pincushion plant; the short, stocky forms of these flowers speak volumes about the prevailing winds here.
At Hakuun-dake junction (白雲岳分岐, Hakuun-dake bunki), a number of traverses meet—one coming up from the green Takane-ga-hara Plateau (高根ヶ原, Takane-ga-hara) and one crossing the gray Hokkai-daira Plateau (北海平, Hokkai-daira). You’ll make a short climb up to the rim of the Mt. Hakuun-dake crater, then cross the crater to the summit on the far side. From the rocky summit of Mt. Hakuun-dake you can see the long line of mountains from Ushiro-Asahi (後旭) to Mt. Hokkai-dake (北海岳, Hokkai-dake) spread before you, like a scene from a folding screen. The pattern of the snow on the mountains should be especially beautiful, if you’re climbing in the earlier parts of the summer. Below, the headwaters of the Yuusetsu-sawa River (融雪沢, Yuusetsu-sawa), will likely sit silent, barren, and dry in the depths of summer.
You’ll head back down the mountain the way you came up. If you have any extra time, it’s not a bad idea to explore the trails radiating out from Hakuun-dake junction—they’re all lovely walks.
There will still be a good deal of snow on the mountains for the first half of the season. The flowers will start blooming from mid-June onwards; because the yellow rhododendron, Japanese locoweed, komakusa bleding-heart, etc. bloom successively, there’s value in visiting twice in a season. The leaves change and the first snows fall at the beginning of September. The contrast between the red whitebeam and the dark green stone pine is especially beautiful.