Yatsugatake

八ヶ岳やつがたけYatsugatake

A compact volcanic range of rocky peaks and dark forests near Tokyo.

Yatsugatake (八ヶ岳, "eight peaks") is a north–south volcanic range about 30 km long on the border of Nagano and Yamanashi prefectures, whose highest peak, Aka-dake, reaches 2,899 m. Its dense network of huts, rocky southern peaks and forested northern hills make it one of the most popular mountain areas within reach of Tokyo.

Elevation: 2,899 mActive volcanoQuasi-national park · 1964100 Famous Mountains

Overview

Yatsugatake rises between the Suwa basin and the upper Chikuma river valley, a chain of volcanic summits whose name refers to many peaks rather than exactly eight. The southern part, with Aka-dake, Amida-dake, Gongen-dake and Yoko-dake, is rocky and alpine; the northern part, north of Natsuzawa pass, is gentler, with dense subalpine forest, moss and small lakes.

The range is the most accessible high mountain area from Tokyo, with more than twenty huts, some of them with hot baths, and year-round use: in winter its cold, relatively snow-poor slopes are a classic training ground for ice climbing and winter mountaineering.

At its foot lie the Yatsugatake plateaus of Nagano and Yamanashi, with resorts, dairy farms and one of the richest concentrations of Jōmon-period sites in Japan.

Landscape and formation

Yatsugatake is a volcanic chain built over the last million years or so along a north–south fissure. The older southern volcanoes have been deeply eroded; a huge collapse of the ancient southern volcano sent a debris avalanche far to the south, towards today's Nirasaki, shaping the long slopes of the Yamanashi side. The northern volcanoes are younger: Kita-Yokodake erupted lava about 800 years ago, and its craters and lava flows are still fresh.

The range divides the Pacific and Sea of Japan drainages and lies on a boundary of dry inland climate, giving cold winters with modest snowfall.

Highlights

Aka-dake
赤岳Aka-dake
The highest peak, 2,899 m, with a hut on the summit and views to Fuji and all three Alps.
Iō-dake
硫黄岳Iō-dake
A broad summit with an enormous explosion crater on its north side and komakusa fields nearby.
Kita-Yokodake
北横岳Kita-Yokodake
The young volcano of the northern range, reached by the Kita-Yatsugatake Ropeway.
Shirakoma-ike
白駒池Shirakoma-ike
A lake at about 2,100 m surrounded by moss-carpeted forest, one of the highest large lakes in Japan.

Ecology

The northern Yatsugatake is famous for its moss forests of fir and hemlock, with hundreds of moss species. The southern ridges support alpine plants, including endemic species. Sika deer grazing has become a problem in the meadows.

Flora

Komakusa
コマクサkomakusa
Large colonies on the gravel between Iō-dake and Yoko-dake.
Yatsugatake-azami
ヤツガタケアザミyatsugatake-azami
A thistle named after the range.
Moss forest
苔の森koke no mori
Shirakoma-ike and its surroundings are known for dense moss carpets under old conifers.

Fauna

Japanese pika
ナキウサギnakiusagi
Lives in boulder fields of the northern range; more often heard than seen.
Sika deer
ニホンジカnihonjika
Common in the forests and increasing in the alpine meadows.

Culture

The foothills were one of the centres of Jōmon culture: obsidian from Wada and Kirigamine was traded widely, and figurines of outstanding quality have been found. Local legend says Yatsugatake was once higher than Fuji, until the jealous goddess of Fuji struck it and shattered its summit into eight peaks. The Suwa Taisha's Onbashira festival, held every six years, uses fir trunks felled in the forests at the foot of Yatsugatake.

Jōmon Venus
縄文のビーナスJōmon no bīnasu
A clay figurine from the Tanabatake site in Chino, the first Jōmon object designated a national treasure (1995).
Togariishi Jōmon Archaeological Museum
尖石縄文考古館Togariishi Jōmon Kōkokan
Museum in Chino displaying the Jōmon Venus and the Masked Goddess figurine.

History

c. 3000 BCE
Jōmon villages flourish on the plateaus at the foot; the Jōmon Venus dates from this period.
c. 800 years ago
Last eruption of Kita-Yokodake.
1964
Yatsugatake-Chūshin Kōgen Quasi-National Park is designated.
1995
The Jōmon Venus becomes a national treasure.

Through the seasons

Spring

Snow lingers on the south-facing slopes into May; larch forests turn green in late May.

Summer

Alpine flowers peak in July; afternoon thunderstorms are common on the southern ridges.

Autumn

Larch turns gold in October; cold, clear days with views to Fuji and the Alps.

Winter

Cold and relatively dry, with frozen waterfalls and icy ridges; a classic winter climbing area, but only for equipped and experienced parties.

Routes and trails

Minotoguchi – Akadake-kōsen – Aka-dake
The standard approach from the south-west, about 5–6 hours via the Kitazawa or Minamisawa valleys; the last section on steep rock and ladders. Usually done with a hut night.
Southern Yatsugatake loop
Aka-dake – Yoko-dake – Iō-dake and back to Akadake-kōsen; 4–5 hours from the huts, with some exposed chains on Yoko-dake.
Kita-Yokodake from the ropeway
From the top station at about 2,240 m, around 1 hour to the summit; easy and suitable for families.
Mugikusa-tōge and Shirakoma-ike
Gentle forest walks in the northern range, 1–3 hours through moss forest.

Practical notes

Trailheads are reached by bus or taxi from Chino, Kobuchizawa and Sakudaira stations; buses run mainly in summer and autumn.
Most huts in the southern range require reservation and some are open year-round.
Kita-Yokodake is monitored by the Japan Meteorological Agency as an active volcano; see its volcano pages for current information.
Winter conditions are severe with strong winds and temperatures well below freezing; crampons and ice axe are essential.

Frequently asked questions

Which is the highest peak of Yatsugatake?

Aka-dake ("red peak"), 2,899 m, named after its reddish volcanic rock. Other main summits include Amida-dake, Yoko-dake, Iō-dake, Tengu-dake and Tateshina-yama.

Is Yatsugatake an active volcano?

Most of the range is extinct, but the Japan Meteorological Agency lists the northern Yokodake (Kita-Yokodake) as an active volcano; its last eruption was about 800 years ago.

How long does it take to climb Aka-dake?

From the Minotoguchi trailhead about 5–6 hours via Akadake-kōsen or Gyōja-goya; most people stay a night in one of the huts and make a loop over Iō-dake and Yoko-dake.

How is Yatsugatake reached from Tokyo?

By the JR Chūō Line limited express to Chino or Kobuchizawa in about two hours, then by bus or taxi to the trailheads.

Sources

1.日本の主な山岳標高 (opens in a new tab) — 国土地理院 (Geospatial Information Authority of Japan)
2.火山登山者向けの情報提供ページ（横岳） (opens in a new tab) — 気象庁 (Japan Meteorological Agency)
3.長野県公式ホームページ (opens in a new tab) — 長野県 (Nagano Prefecture)
4.山梨県公式ホームページ (opens in a new tab) — 山梨県 (Yamanashi Prefecture)