Chisenupuri (チセヌプリ, Chisenupuri) is a mountain tucked neatly in the middle of the Niseko Mountains (ニセコ連峰, Niseko-renpou), a perennial favorite with backcountry skiers, both local and tourist.
It’s said that Chisenupuri’s name comes from the Ainu chise-nupuri, meaning ‘house[-shaped] mountain’. Specifically, the mountain has the distinct shape of old Ainu thatched houses of sasa bamboo and reeds. Among the mountain's attractions are Shinsen-numa Marsh (神仙沼, Shinsen-numa), on the northern slopes of the mountain, known for its variegated wetland vegetation. In fall the changing colors of the leaves on the fringes of the marsh are truly striking. Though the trek to the summit is quite short, the sights are many, from Shinsen-numa Marsh to Naga-numa Pond (長沼, Naga- numa).
You’ll start the hike at Shinsen-numa Marsh Entrance (神仙沼入口, Shinsen-numa iriguchi) on the Niseko Panorama Line (ニセコパノラマライン, Niseko panorama-rain) road. There are two entrances to the park, but whichever you take doesn’t matter—they lead to the same place. At the height of summer and at the changing of the leaves, Shinsen-numa Marsh is very, very popular; so if you’re looking for a quiet hike it’s a better idea to visit on a weekday.
Shinsen-numa Marsh is a low alpine wetland occupying 2.5 hectares on a plateau at about 770 meters above sea level. It’s rimmed with Glehn’s spruce and laced with the usual alpine suspects: Aleutian avens and dwarf stone pine, for example. Along the tree-lined path, however, overuse is starting to become a concern. So while you’re here, try to avoid behaviors that could damage the fragile wetland environment.
From Shinsen-numa Marsh you’ll head towards Naga-numa Pond up a trail lined with forked viburnum and Japanese wood poppy. Shortly thereafter, you’ll pass a trail joining yours from the right and come to Naga-numa Pond itself. Like at Shinsen-numa Marsh, over the pond you should be able to see the house-shaped Chisenupuri standing before you. You’ll walk along the edge of the pond and the head due south, arriving shortly at Mt. Shakunage-dake junction (シャクナゲ岳分岐, Shakunage-dake-bunki), and a little ways after that, at Chisenupuri junction (チセヌプリ分岐, Chisenupuri-bunki), from which you can traverse to the hot springs at Konbu Onsen (昆布温泉, Konbu onsen).
From here, the steep climb up the western flank of Chisenupuri begins. At the top of the hike’s only real climb, you’ll arrive at the flat summit of Chisenupuri.
From the summit you’ll have excellent views to the nearby peaks of Mt. Shakunage-dake (シャクナゲ岳, Shakunage-dake) and Mt. Mekunnai-dake (目国内岳, Mekunnai-dake); but you might also be surprised to find, tucked in the pine bush nearby, a small pond. In mid-June you’ll find white skunk cabbage and oriental swamp pink blossoming quietly up here.
You’ll descend by the trail that you took up.
These days, you can also descend by the mountain’s steep eastern face and emerge on the Niseko Panorama Line road, near the top of the pass between Chisenupuri and neighboring Nitonupuri (ニトヌプリ). You'll be sharing the road with cars, but if you’re the sort of person who doesn’t like walking the same trail twice, this route can be especially beautiful in the fall. From the summit back to the trailhead at Shinsen-numa Marsh Entrance by this route takes about an hour and a half. If you really want to enjoy the Niseko Mountains thoroughly, you can also descend Chisenupuri’s southern face—this takes you to the hot springs at Yumoto Onsen. A fourth possibility is to return to Shakunage-dake junction and traverse over Mt. Shakunage-dake, from which you can descend to Niimi Onsen hot springs. Both Niimi Onsen and Yumoto Onsen feature overnight accommodation.
There will likely be a lot of snow until around late June. Around Shinsen-numa Marsh you’ll see a good deal of oriental swamp pink, white skunk cabbage, Aleutian avens, and hare’s-tail cottongrass from June onwards; Siebold’s plantain lily and Arctic iris will bloom in August. The leaves start to change in late October. On weekends and holidays Shinsen-numa Marsh is very busy with tourists from Sapporo. If you’re looking for peace, skip the height of tourist season and visit the mountain in the late fall.