Mt. Kariba-yama (狩場山, Kariba-yama) is the highest mountain in the southern part of Hokkaido. It’s name comes from the Ainu karinba-ush-nupuri, meaning ‘mountain where there are cherry (sakura) trees’. It makes you wonder if there were more cherry trees around here in the past. The mountain gets a lot of snow in winter, so the two rivers that make their headwaters here, the Chihase-gawa (千走川) and the Sukki-gawa (須築川), are among the clearest in Hokkaido. The mountain is surrounded by other peaks above 1000 meters--Mt. Higashikariba-yama (東狩場山 Higashi-kariba-yama), Mt. Fumonnai-dake (フモンナイ岳, Fumonnai-dake), and Mt. Okotsunai-dake (オコツナイ岳, Okotsunai-dake), to name a few--so the whole area feels like a single huge massif covered all over by Japanese beech.
There are five trails up the mountain, but the Baba-gawa Trail (馬場川コース, Baba-gawa-kousu) has been closed, and the Chihase Old Trail (千走旧道, Chihase-kyuudou) is also falling into disrepair. In this guide you’ll climb the shortest trail, the Chihase New Trail (千走新道, Chihase-kyuudou).
From Shimamaki (島牧) district you’ll head up a forest road following the Chihase-gawa River, through the Garo Marsh (賀老高原, Garou-kogen) campsite, and find the trailhead at the end of the road. On Kariba-yama the Japanese beech treeline is at about 750 meters above sea level, so shortly after you start climbing, the beech will disappear and be replaced by forests of Erman’s birch.
Slowly the trail will make its way west and then north as you begin to climb up the steep slope atop a ridge. Where the eastern slope seems to rise diagonally above you, you’ll find a small field where snow may remain as late as August; as the snow melts, though, flowers will bloom in its place.
In a snowy valley a little ways above here, you’ll come to the Makomanai Trail junction (真駒内コース分岐, Makomanai-kousu bunki). In the grassy fields here you’ll see unbroken clusters of Aleutian mountainheath, as well as meadow buttercup, short-stipule violet, and Kamchatkan St. John’s wort, among other flowers.
You’ll soon come to the narrow top of the ridgeine around Minamikariba (南狩場), a small secondary peak; shortly thereafter you'll find yourself in the vicinity of the summit. Along the gently-sloped ridgetop you’ll pass across more fields and a small pond where deer cabbage have laid down roots. Just past the point where the Chihase-Old Trail merges with your trail, you’ll arrive at the summit of Mt. Kariba-yama.
At the summit your eyes will be drawn down into the huge deep valley to the southwest. This is the Sukki-gawa gully, a river known for its difficulty in navigating upstream. It's thickly laid with forests of deep green Japanese beech, a typical sight in the mountains of Southern Hokkaido.
You’ll head back down the trail you came up.
The Chihase Old Trail is quite a different beast, starting near the Garo Marsh campsite and wending endlessly through beautiful forests of Japanese beech. As the years go by and hikers elect more and more to hike the shorter Chihase New Trail, the Old Trail is being overgrown by sasa bamboo. If you choose to climb this Old Trail, make sure to bring map and compass to navigate if need be.
From the summit as well a long trail stretches out to the west, towards the Motsuta-misaki Cape (茂津多岬, Motsuke-misaki). Walking all the way from the mountain to the Sea of Japan is a worthwhile, if arduous, pursuit.
The Japanese beech will bloom at the end of June, but along the ridgelines at this point there will still be a lot of snow; so if you’re hiking in June make sure you have some experience with hiking on snow. Through July and August the snow will melt and the flowers will bloom one by one. The best time for viewing the changing leaves on the beech trees is in mid-October.