Mount Shibutsu was added to Your Favorites!
Oze NP, Gunma
Claim this place to tell your story your way.
On July 16, 1929, botanist Hiroshi Hara collected Oze-so on Mt. Shibutsu. In 1930, Takenoshin Nakai described it as a new species—and a new genus, Japonolirion.
Oze-so is a botanical loner: Japonolirion osense is the only species in its genus, endemic to Japan and known from just 3 separated areas—Mt. Shibutsu, Mt. Tanigawa and Hokkaido’s Teshio Mountains.
A relative of Europe’s edelweiss, narrow-leaved usuyukiso grows around Mt. Shibutsu and Tanigawa. Japan’s Red List classifies it as Vulnerable, with fewer than 1,000 flowering plants estimated.
Before the Yamanohana trail opened in 1932, the usual way up from Ozegahara was to climb Mujina-sawa; from Fujiwara, climbers ascended Kari-koya-sawa. Both early approaches followed streams, not marked trails.
Most peaks around Oze are volcanic, but Mt. Shibutsu is not: its upper slopes expose serpentinite formed about 230 million years ago. Weathering turns the rock, originally dark green, a rusty brown.
Mt. Shibutsu’s tree line sits near 1,700 m—about 500 m below that on nearby volcanic Mt. Hiuchi. Serpentinite’s chemistry is one reason trees stop early, leaving open alpine slopes on a 2,228-m peak.
In 2011, botanists recorded Oze-so in upper Mujina-sawa, where it had not been documented before. The steep, brushy valley is hard to reach and remains one of Mt. Shibutsu’s least-explored corners.
Oze’s conservation vision identifies Mt. Shibutsu as a refuge for Ice Age relict plants as well as serpentinite specialists. Some flowers on this Gunma summit are survivors from Japan’s colder past.
Mountain writer Kotaro Kogure recorded different names for the same peak: Shibutsu in Togura and Hinoemata, but Takekura on the Fujiwara side. The summit’s name depended on which community you asked.
The steep eastern trail from Yamanohana to the summit closed in 1989 after erosion and safety concerns; it reopened in August 1997 after repairs. Its upper section is now ascent-only to protect plants and hikers.
At about 1,800 m, erosion stripped away so much soil that sowing seeds or transplanting plants is difficult. Gunma crews first install retaining works and vegetation mesh to rebuild the growing base on Mt. Shibutsu.
The saddle between Mt. Shibutsu and Hinazaki-yama once connected Oze with Fujiwara. In the 1960s, a 3.8-km trail there was rebuilt as a route linked to an Oze reservoir survey—an unexpected overlap of mountaineering and hydropower planning.
