Joshinetsu Kogen National Park

上信越高原国立公園じょうしんえつこうげんこくりつこうえんJōshin'etsu Kōgen Kokuritsu Kōen

Volcanic plateaus, snow country and hot springs on the Japan Alps' eastern flank

Jōshin'etsu Kōgen National Park spans the volcanic highlands and mountain ranges where Gunma, Nagano and Niigata meet. Designated in 1949, it takes in the Shiga Kōgen plateau, the active volcanoes Asama-yama and Kusatsu-Shirane, the rock walls of Tanigawa-dake and a string of famous hot springs and ski resorts.

Elevation: 2,568 mArea: 1,510.53 km²National park · 1949Ramsar wetland · 2015

Overview

Jōshin'etsu Kōgen is a large park stretching across the central mountains of Honshu, north of Karuizawa and north-west of Tokyo. It consists of several areas: the volcanic Asama-yama on the Gunma–Nagano border; the Kusatsu-Shirane volcano and the Shiga Kōgen plateau with its dozens of ponds and moors; the Azumaya-san and Sugadaira highlands; the Naeba-san massif; and, along the Gunma–Niigata border, the Tanigawa range.

The landscape combines high, rolling plateaus with sharp peaks and active volcanoes. Cold winter monsoon winds bring deep snow to the northern parts, making the park home to major ski areas such as Shiga Kōgen, which hosted alpine events of the 1998 Nagano Olympics. The volcanic heat supports celebrated hot springs, from Kusatsu and Manza to the monkeys' onsen at Jigokudani.

Designated in 1949, the park originally also included the Myōkō and Togakushi mountains, added in 1956. In 2015 they were separated as a national park of their own, and Jōshin'etsu Kōgen was reorganised around its remaining areas.

Landscape and formation

The park straddles the volcanic front of central Japan. Asama-yama (2,568 m) is a stratovolcano with a long record of eruptions; in 1783 a catastrophic eruption produced a pyroclastic flow and debris avalanche that buried the village of Kanbara and the Onioshidashi lava flow, whose jumbled black rocks are now a park. Kusatsu-Shirane is a group of volcanoes with the turquoise, acidic crater lake Yugama; its Motoshirane cone erupted unexpectedly in 2018.

The Shiga Kōgen plateau is built of old lava flows from Shiga and Yokote volcanoes, whose uneven surfaces trap countless ponds and bogs. By contrast, the Tanigawa range is non-volcanic, a ridge of older rocks on the main Japanese watershed, where heavy snow and avalanches have carved steep gullies and rock walls.

Highlights

Asama-yama
浅間山Asama-yama
An active 2,568 m stratovolcano above Karuizawa, one of the most closely monitored volcanoes in Japan.
Tanigawa-dake
谷川岳Tanigawa-dake
A 1,977 m peak on the Gunma–Niigata border with the Ichinokura-sawa rock walls; a ropeway from Doai gives easy access to its ridge.
Shiga Kōgen
志賀高原Shiga Kōgen
A volcanic plateau of ponds, moors and forests at 1,400 to 2,000 m, a UNESCO biosphere reserve and a major ski area.
Yugama and Kusatsu-Shirane
湯釜・草津白根山Yugama, Kusatsu-Shirane-san
An emerald-green crater lake of highly acidic water on an active volcano above Kusatsu Onsen.
Onioshidashi
鬼押出しOnioshidashi
A field of black lava blocks on Asama's northern foot from the 1783 eruption.
Naeba-san
苗場山Naeba-san
A 2,145 m mountain with a flat summit plateau covered by alpine moor and hundreds of small ponds.
Jigokudani snow monkeys
地獄谷野猿公苑Jigokudani Yaen-kōen
A steep valley where wild Japanese macaques bathe in hot springs, especially in winter.

Nature

MountainsMount AsamaAsama-yamaThe smoking volcano above Karuizawa, witness of the 1783 catastrophe.MountainsTanigawa-dakeTanigawa-dakeTwin summits on the divide of Honshū and Japan's most notorious rock walls.

Ecology

Altitude and snow create a mosaic of forest types: beech on the snowy northern slopes, larch and birch on the volcanic plateaus, subalpine fir and dwarf pine on the high ridges. The ponds and bogs of Shiga Kōgen, Naeba-san and the Yoshigadaira wetlands on Kusatsu-Shirane support a rich moor flora; Yoshigadaira became a Ramsar site in 2015.

The park's mammals include Japanese macaques, famously at Jigokudani, Asian black bears, serows and increasing numbers of sika deer. Golden eagles nest in the Tanigawa range, and alpine butterflies occur on the higher peaks.

Flora

Renge azalea of Kazawa
鹿沢のレンゲツツジKazawa no renge-tsutsuji
Large stands of the orange Japanese azalea colour the Kazawa and Yunomaru highlands in June.
Kusatsu-Shirane rhododendrons
草津白根のシャクナゲKusatsu-Shirane no shakunage
Rhododendron communities on the volcano's slopes, flowering in early summer.
Naeba-san moor flora
Cotton grass, sundews and alpine flowers on the summit plateau of Naeba-san.
Komakusa
コマクサkomakusa
The alpine bleeding heart grows on the volcanic gravel of Kusatsu-Shirane and Asama's outer rim.

Fauna

Japanese macaque
ニホンザルnihonzaru
The troops at Jigokudani are the world's best-known bathing monkeys.
Asian black bear
ツキノワグマtsukinowaguma
Common in the forests, particularly in autumn on the plateaus.
Japanese serow
ニホンカモシカnihon-kamoshika
Found on the rocky slopes of Tanigawa and the Shiga mountains.
Golden eagle
イヌワシinuwashi
Nests in the remote cliffs of the Tanigawa range.

Culture

The highlands have long been crossed by trade routes between the Kantō plain, Shinano and Echigo, including the Nakasendō at the foot of Asama-yama. The 1783 Tenmei eruption of Asama, which killed well over a thousand people and contributed to famine, is remembered at Kanbara, where the stone steps of the Kannon hall saved the few survivors.

Hot-spring culture is central: Kusatsu is one of Japan's most famous onsen towns, with its central Yubatake and the traditional yumomi ritual of cooling the water with boards. The snow country around Naeba and Tanigawa, and the remote Akiyama-gō valley, preserve old mountain village traditions, while Shiga Kōgen and Sugadaira grew into ski and sports resorts in the 20th century.

Kanbara Kannon-dō
鎌原観音堂Kanbara Kannon-dō
The hillside temple hall where survivors of the 1783 eruption took refuge; excavations uncovered the buried steps.
Kusatsu Onsen Yubatake
草津温泉湯畑Kusatsu Onsen Yubatake
The steaming 'hot-water field' at the centre of Kusatsu, at the eastern foot of Kusatsu-Shirane.
Tanigawa-dake Mountain Museum
谷川岳山岳資料館Tanigawa-dake Sangaku Shiryōkan
Museum at Doai on the history of climbing and accidents on Tanigawa-dake.

History

1783
The Tenmei eruption of Asama-yama buries Kanbara village and forms the Onioshidashi lava flow.
1931
The Shimizu Tunnel opens beneath the Tanigawa range, bringing climbers to Tanigawa-dake.
1949
Jōshin'etsu Kōgen National Park is designated on 7 September.
1956
The Myōkō and Togakushi mountains are added to the park.
1980
Shiga Kōgen is designated a UNESCO biosphere reserve.
1998
Shiga Kōgen hosts alpine skiing events of the Nagano Winter Olympics.
2015
The Myōkō-Togakushi area becomes a separate national park; the Yoshigadaira wetlands are listed under the Ramsar Convention.
2018
Motoshirane on Kusatsu-Shirane erupts without warning near a ski area.

Through the seasons

Spring

The Shiga-Kusatsu road reopens through walls of snow in spring; skiing continues on Shiga Kōgen's upper slopes into May.

Summer

A cool retreat from the Kantō heat: hiking on the Shiga plateau, Naeba-san and Tanigawa-dake, and azaleas in June.

Autumn

Colours arrive on the plateaus in early October; Tanigawa's slopes and the Kusatsu area follow later in the month.

Winter

Deep snow in the northern and western areas and some of Japan's largest ski areas; snow monkeys bathe at Jigokudani.

Routes and trails

Tanigawa-dake via the Tenjin ridge
From the Tanigawa-dake Ropeway top station along the ridge to the twin summits; about 5 hours return, exposed in bad weather.
Asama outer rim: Kurofu-yama
From Asama-sansō or Kurumasaka Pass to viewpoints on the outer crater rim; the inner summit depends on alert levels.
Shiga Kōgen pond walks
Trails linking the ponds around Ichinuma, Kido-ike and Onuma-ike, plus the lift to Higashidate-yama.
Naeba-san from Kagura or Akiyama-gō
A long climb to the summit plateau and its boardwalks among ponds; a hut on top allows an overnight stay.
Jigokudani path
A forest walk of about 30 minutes from Kanbayashi Onsen to the monkey park, snowy in winter.

Practical notes

The Hokuriku Shinkansen serves Karuizawa, Sakudaira and Nagano; the Jōetsu Shinkansen serves Jōmō-Kōgen and Echigo-Yuzawa for Tanigawa and Naeba.
Asama-yama and Kusatsu-Shirane are active volcanoes with changing restricted zones; check the Japan Meteorological Agency's alert levels and local notices.
Some high roads, including the Shiga-Kusatsu route over Shibutōge, are closed in winter.
Tanigawa-dake is dangerous in poor visibility and in snow; many accidents occur on the popular ridge route.
Do not touch or feed the monkeys at Jigokudani, and keep to the paths.

Frequently asked questions

What does Jōshin'etsu mean?

The name combines the first characters of the old provinces Kōzuke (Gunma), Shinano (Nagano) and Echigo (Niigata), whose borders meet in the park. Kōgen means highland or plateau.

Can you climb Asama-yama?

Asama-yama is one of Japan's most active volcanoes, and access to its summit crater depends on the current alert level. Hikers usually climb the neighbouring outer-rim peaks such as Kurofu-yama, which look into the crater.

Where are the snow monkeys?

At Jigokudani Yaen-kōen on the western edge of the Shiga highlands, Japanese macaques bathe in a hot spring in winter. It is reached on foot from Kanbayashi Onsen near Yudanaka.

Why is Tanigawa-dake notorious?

Its north-east face, the Ichinokura-sawa, is one of Japan's great rock walls, and the mountain's sudden weather changes have claimed more climbers' lives than any other peak in the world, according to records kept since the 1930s.

Is Myōkō still part of this park?

No. The Myōkō and Togakushi mountains were part of Jōshin'etsu Kōgen from 1956 until 2015, when they became a separate national park, Myōkō-Togakushi Renzan.

Sources

1.上信越高原国立公園 (opens in a new tab) — 環境省
2.国立公園の概要 (opens in a new tab) — 環境省
3.Joshin'etsukogen National Park (opens in a new tab) — Ministry of the Environment, Japan
4.日本活火山総覧：浅間山 (opens in a new tab) — 気象庁