National Parks · Gunma, Fukushima, Niigata, Tochigi
Oze National Park
尾瀬国立公園おぜこくりつこうえんOze Kokuritsu KōenBoardwalks across the moor where Japanese conservation began
Oze National Park protects Ozegahara, the largest high moor on Honshu, together with Lake Ozenuma and the surrounding peaks on the borders of Gunma, Fukushima, Niigata and Tochigi. Part of Nikko National Park from 1934, it became a national park in its own right in 2007 and is a cradle of Japan's nature-conservation movement.
Overview
Oze lies at about 1,400 to 1,700 m in the mountains where Gunma, Fukushima, Niigata and Tochigi meet, some 150 km north of Tokyo. Its centre is Ozegahara, a broad basin of Sphagnum bog, pools and streams about 6 km long, flanked by the volcano Hiuchigatake to the north-east and the serpentine peak of Shibutsu-san to the south-west. To the east lies Ozenuma, a lake dammed by Hiuchigatake's lava. Further north, the Aizu-Komagatake and Tashiro-yama areas have their own summit moors.
A network of wooden boardwalks, some 65 km long in total, carries hikers across the wetlands without trampling the peat. Mountain huts inside the park, a rarity in a Japanese wetland, allow overnight stays and early-morning walks in the mist that often fills the basin.
Oze was part of Nikko National Park from 1934 and was designated as a separate park on 30 August 2007. It is one of the most loved landscapes of eastern Japan, immortalised in the 1949 song Natsu no Omoide (Summer Memories), and a symbol of how a nature-conservation movement could stop development.
Landscape and formation
Ozegahara formed when volcanic activity at Hiuchigatake dammed the upper Tadami River valley, creating a lake that gradually filled with sediment and peat over some 8,000 years. The peat has grown into a raised bog with hummocks, hollows and countless small ponds (chitō), each with its own floating vegetation. Ozenuma, at 1,665 m, remains open water.
Hiuchigatake (2,356 m) is a young volcano, the highest peak in Tōhoku. Shibutsu-san (2,228 m) is made of serpentinite, an ultramafic rock poor in nutrients and rich in magnesium, which supports a distinctive flora of specialist plants. The Tadami River leaves the basin over the waterfalls Sanjō-no-taki and Hiraname-no-taki.
Highlights
Ozegahara
尾瀬ヶ原OzegaharaThe largest high moor on Honshu, crossed by parallel boardwalks with views of Shibutsu-san and Hiuchigatake.
Ozenuma
尾瀬沼OzenumaA lake at 1,665 m at the foot of Hiuchigatake, with the Ōe marsh and its summer day lilies on the eastern shore.
Hiuchigatake
燧ヶ岳HiuchigatakeA 2,356 m volcano between Ozegahara and Ozenuma, the highest peak in Tōhoku.
Shibutsu-san
至仏山Shibutsu-sanA 2,228 m serpentine mountain above Ozegahara with rare alpine plants and seasonal access rules.
Aizu-Komagatake
会津駒ヶ岳Aizu-KomagatakeA 2,133 m peak in the north of the park with a gently sloping summit moor and ponds.
Sanjō-no-taki
三条ノ滝Sanjō-no-takiA powerful waterfall of about 100 m where the Tadami River leaves Ozegahara.
Ecology
Ozegahara is exceptionally rich in plants, including many bog and alpine plants at the southern limit of their range. The flowering sequence begins with skunk cabbage in the melting snow and continues through cotton grass and sundews to the yellow Nikkō-kisuge day lilies of July and the gentians of late summer. Oze-sō, a small lily-like plant, was first discovered here and grows on the serpentine of Shibutsu-san and at very few other sites.
Pressures on the ecosystem come from visitors, deer and climate. Sika deer, formerly absent, reached Oze in the 1990s and feed on the moor vegetation; fences and culling are used to limit damage. Asian black bears regularly cross the moor, especially when the skunk cabbage fruits in summer.
Flora
Skunk cabbage
ミズバショウmizubashōWhite spathes that cover the wet ground as the snow melts from late May, the symbol of Oze.
Nikkō-kisuge
ニッコウキスゲNikkō-kisugeYellow day lilies that turn the Ōe marsh and parts of Ozegahara golden in July.
Oze-sō
オゼソウOze-sōA rare plant of serpentine soils, named after Oze, where it was discovered.
Hosoba-hina-usuyukisō (dwarf edelweiss)
ホソバヒナウスユキソウHosoba-hina-usuyukisōA dwarf edelweiss that grows only on the serpentine of Shibutsu-san and nearby mountains.
Maries' fir forest
オオシラビソ林ōshirabiso-rinSubalpine fir forest on the slopes around the moor, with beech forest lower down.
Fauna
Asian black bear
ツキノワグマtsukinowagumaSeen crossing the moor; bells and bear awareness are recommended on the boardwalks.
Japanese serow
ニホンカモシカnihon-kamoshikaLives in the forests and on the slopes of the surrounding peaks.
Sika deer
ニホンジカnihonjikaA recent arrival whose grazing threatens the skunk cabbage and day lilies.
Moor dragonflies
Pools on the moor host northern dragonflies and damselflies in summer.
Culture
Oze was historically a pass between the Aizu region and Kōzuke (Gunma), used for trade in salt and goods. In 1890 Hirano Chōzō settled at Ozenuma and opened the first mountain hut; his family, over three generations, led resistance to hydropower plans that would have flooded the moor. In 1971 Hirano Chōsei appealed directly to the head of the newly founded Environment Agency, Ōishi Buichi, who halted a road being built across the area.
The tradition of taking one's rubbish home (gomi mochikaeri) began in Oze in 1972 and spread throughout Japan's mountains. The song Natsu no Omoide, with its opening line about remembering distant Oze, is known to almost every Japanese school child.
Chōzō-goya
長蔵小屋Chōzō-goyaThe historic hut on the shore of Ozenuma founded by Hirano Chōzō, still run as a mountain lodge.
Oze-numa Visitor Center
尾瀬沼ビジターセンターOzenuma Bijitā SentāVisitor centre at the eastern end of Ozenuma with nature exhibits and guided walks.
Yamanohana Visitor Center
尾瀬山の鼻ビジターセンターOze Yamanohana Bijitā SentāAt the western edge of Ozegahara, the entry point from Hatomachi Pass.
History
c. 8,000 years ago
Peat begins to accumulate in the basin dammed by Hiuchigatake's volcanic activity.
1890
Hirano Chōzō settles at Ozenuma and opens the first hut.
1934
Oze is included in the new Nikko National Park.
1949
The song Natsu no Omoide makes Oze famous nationwide.
1960
Oze is designated a Special Natural Monument.
1971
A road-building project through Oze is halted after public protest.
1972
The campaign to carry out all litter begins in Oze.
2005
Oze is listed as a Ramsar wetland.
2007
Oze National Park is designated on 30 August, separated from Nikko National Park.
Through the seasons
Spring
Snow covers the moor until May; the season opens with skunk cabbage from late May to mid-June while snow still lies on the peaks.
Summer
Day lilies in July, alpine flowers on Shibutsu-san and Hiuchigatake, and morning mist over the moor; the busiest time.
Autumn
From mid-September the moor's grasses turn gold and red, followed by maple and birch colour on the slopes in early October.
Winter
Deep snow of several metres; huts and access roads close, and the area is left to experienced ski tourers.
Routes and trails
Hatomachi Pass to Ozegahara
A descent of about an hour through forest to Yamanohana, then level boardwalks across the moor to Ushikubi and Ryūgū.
Ozenuma circuit
A boardwalk loop of about 3 to 4 hours around the lake from Numayama Pass or the Ōshimizu trailhead.
Hiuchigatake from Ozenuma
A steep climb via the Nagahama ridge to the twin summits of Shibakura-dake and Manaita-gura.
Shibutsu-san from Yamanohana
A climb over slippery serpentine rock to the summit; seasonal closures and one-way rules apply.
Aizu-Komagatake from Hinoemata
A climb through beech forest to a summit moor with ponds and a hut.
Practical notes
- From Tokyo, the Jōetsu Shinkansen to Jōmō-Kōgen and a bus to Tokura give access from the Gunma side; the Fukushima side is reached via Aizu-Kōgen Oze-guchi station and Hinoemata.
- Private cars are restricted on the final approach roads in the main season; use the shuttle buses from Tokura or Numayama Pass parking.
- Walk only on boardwalks and keep to the right when passing; boardwalks are narrow and slippery in rain.
- Take all rubbish out with you; huts have limited facilities, and toilets ask visitors for a contribution towards wastewater treatment.
- Weather at 1,400 m and above can be cold and wet even in summer; bring rain gear and warm layers.
Frequently asked questions
When is the best time to visit Oze?
The season runs from late May, when snow melts and the skunk cabbage flowers, to October. Day lilies colour the moor in July, and in late September the grasses turn gold in the 'grass autumn' (kusa-momiji). In winter the area is closed by deep snow.
Why did Oze become a separate national park?
In 2007 Oze was separated from Nikko National Park and combined with the Aizu-Komagatake and Tashiro-yama areas to form Japan's 29th national park, recognising the wetlands as a distinct natural region.
Can you drive into Oze?
No. Roads end at trailheads such as Hatomachi Pass in Gunma and Numayama Pass in Fukushima, and private cars are restricted on the final approach roads in the main season; shuttle buses and taxis complete the journey.
Why is Oze important for Japanese conservation?
Plans to flood the moor for hydropower and to build a road through it were fought from the early 20th century to the 1970s. The campaign to take all litter home, now a national norm for hikers, began in Oze in 1972.
Can Shibutsu-san be climbed at any time?
No. To protect its fragile serpentine vegetation during snowmelt, the trail is closed in spring and one-way rules apply on part of the route; check current rules before visiting.
Related
Sources
- 1.尾瀬国立公園 (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.Oze National Park (opens in a new tab) — Ministry of the Environment, Japan
- 4.Ramsar Sites Information Service (opens in a new tab) — Ramsar Convention Secretariat