National Parks · Hokkaido
Hidaka-sanmyaku Erimo Tokachi National Park
日高山脈襟裳十勝国立公園ひだかさんみゃくえりもとかちこくりつこうえんHidaka-sanmyaku-Erimo-Tokachi Kokuritsu KōenThe spine of Hokkaido, from glacial cirques to the Pacific cape
Hidaka-sanmyaku Erimo Tokachi National Park, designated in 2024, protects the Hidaka mountains, the rugged spine of southern Hokkaido, from the Tokachi uplands down to Cape Erimo on the Pacific. At 2,456 km² it is Japan's largest national park and one of its least developed, a range almost without roads, huts or lifts.
Overview
The Hidaka mountains run for about 140 km from the Karikachi Pass in central Hokkaido south to Cape Erimo, where they plunge into the Pacific. They separate the Hidaka coast to the west from the Tokachi plain to the east and form a nearly unbroken wall of sharp ridges, reaching 2,052 m at Poroshiri-dake. The national park covers the whole range, the peridotite mountain Apoi-dake near Samani, and the coast of Erimo.
The park was designated on 25 June 2024. Its core had been protected since 1981 as a quasi-national park; the upgrade added large forest areas on the Tokachi side and made it, at 2,456 km², the largest national park in Japan. The Ministry of the Environment describes it as the country's largest continuous primeval forest ecosystem.
Unlike most Japanese mountain parks, Hidaka has almost no infrastructure: a few trailheads at the ends of forest roads, a handful of basic huts and routes that follow rivers upstream. It is valued precisely for this remoteness, and for landscapes shaped by glaciers, which in Hokkaido are seen nowhere else so clearly.
Landscape and formation
The Hidaka mountains are not volcanic. They are a collision zone where two crustal blocks met, lifting and overturning deep crust along the range; metamorphic and plutonic rocks exposed along the axis record conditions tens of kilometres below the surface. At the southern end, the Horoman peridotite of Apoi-dake is a slice of the Earth's upper mantle pushed to the surface, one of the best-preserved in the world.
During the last Ice Age, small glaciers formed below the highest ridges and carved bowl-shaped cirques, among them the Nanatsu-numa cirque with its small lakes under Poroshiri-dake and the cirques of Tottabetsu-dake and Kamuiekuuchikaushi-yama. The rivers draining the range, the Saru, Niikappu, Tottabetsu and Satsunai, cut deep, steep valleys. At Cape Erimo, uplifted marine terraces end in cliffs and a chain of reefs extending about 2 km out to sea.
Highlights
Poroshiri-dake
幌尻岳Poroshiri-dakeThe highest peak of the range (2,052 m), one of the 100 Famous Mountains of Japan, reached by a long approach with repeated river crossings.
Kamuiekuuchikaushi-yama
カムイエクウチカウシ山Kamuiekuuchikaushi-yamaA 1,979 m peak whose Ainu name means 'the mountain where bears fall'; climbed via the Satsunai River and the Hachi-no-sawa cirque.
Apoi-dake
アポイ岳Apoi-dakeAn 810 m peridotite mountain near Samani with a unique alpine flora at low altitude; core of the Mount Apoi UNESCO Global Geopark.
Cape Erimo
襟裳岬Erimo-misakiThe southern end of the Hidaka range, with reefs stretching into the Pacific, strong winds and a seal colony.
Nanatsu-numa cirque
七ツ沼カールNanatsu-numa kāruA glacial cirque with small tarns below Poroshiri-dake, the best-known glacial landform in Hokkaido.
Ecology
The park contains Japan's largest area of continuous natural forest, from the mixed broadleaf-conifer forests of the lowlands through Erman's birch to the dwarf-pine belt and alpine meadows. Isolation and the unusual rocks have produced many endemic plants, especially on the peridotite of Apoi-dake and on the serpentinite and limestone of the southern range.
The mountains are one of the largest brown-bear habitats in Japan, and pikas live in the boulder fields and cirques. Along the rivers, the endangered Blakiston's fish owl hunts, while at Cape Erimo Japan's largest colony of Kuril harbour seals rests on the reefs.
Flora
Hidaka-sō
ヒダカソウHidaka-sōA small white-flowered alpine plant endemic to the southern Hidaka mountains around Apoi-dake, critically endangered by poaching.
Chosenia willow
ケショウヤナギkeshō-yanagiA willow of gravelly river beds on the Tokachi side, whose young shoots are covered in white wax.
Kita-goyō pine
キタゴヨウkita-goyōA five-needle pine forming open stands on rocky ridges, especially on the peridotite of Apoi-dake.
Hidaka-mitsuba-tsutsuji
ヒダカミツバツツジHidaka-mitsuba-tsutsujiA purple-flowered azalea of Hokkaido named after the Hidaka region, blooming in late spring.
Fauna
Brown bear
ヒグマhigumaWidespread and frequently met in cirques and valleys; the range is one of the bear's core habitats in Hokkaido.
Northern pika
エゾナキウサギEzo-naki-usagiAn Ice Age relict living in boulder fields and cirque floors.
Kuril harbour seal
ゼニガタアザラシzenigata-azarashiJapan's largest colony rests on the reefs off Cape Erimo all year round.
Blakiston's fish owl
シマフクロウshima-fukurōBreeds along forest rivers on both sides of the range.
Hime-chamadara-seseri
ヒメチャマダラセセリHime-chamadara-seseriA skipper butterfly found in Japan only on Apoi-dake, protected as a national endangered species.
Culture
The Hidaka region is one of the heartlands of Ainu culture, above all the Saru River valley on the western side of the range; many peak names, such as Poroshiri ('great mountain') and Kamuiekuuchikaushi, are Ainu. The Ainu travelled the rivers deep into the mountains to hunt and fish.
In modern times the range became a proving ground for Japanese mountaineering because of its difficulty, with university clubs pioneering routes up the river valleys. Its dangers are part of that history: in 1970, three members of a student party were killed by a brown bear on Kamuiekuuchikaushi-yama, a case still cited in bear-safety training. At Cape Erimo, the long restoration of the eroded headland by fishing families, who planted grass and black pine from the 1950s to bring back kelp and fish, is regarded as a model of community-led reforestation.
Apoi Geopark Visitor Center
アポイ岳ジオパークビジターセンターApoi-dake Jiopāku Bijitā SentāVisitor centre at the foot of Apoi-dake in Samani, explaining the mantle rocks and the endemic flora.
Kaze-no-Yakata (Cape Erimo)
襟裳岬「風の館」Erimo-misaki Kaze-no-yakataA wind museum built into the hillside at Cape Erimo, with seal-watching telescopes.
Hidaka Mountains Center
日高山脈山岳センターHidaka Sanmyaku Sangaku SentāA mountaineering base and information centre in Hidaka town at the northern end of the range.
History
Ainu period
Ainu communities along the Saru and other rivers use the valleys for hunting and fishing.
1952
The alpine plant communities of Apoi-dake are designated a Special Natural Monument.
1953
Fishermen begin reforesting the barren hills of Cape Erimo.
1970
A bear attack on Kamuiekuuchikaushi-yama kills three student climbers.
1981
The Hidaka-sanmyaku Erimo Quasi-National Park is designated.
2015
Mount Apoi Geopark becomes a UNESCO Global Geopark.
2024
Upgraded and enlarged into Hidaka-sanmyaku Erimo Tokachi National Park on 25 June, Japan's largest.
Through the seasons
Spring
Snow persists in the high range into June; on Apoi-dake alpine flowers bloom from May. Rivers are swollen with snowmelt, making valley routes dangerous.
Summer
The main climbing season from July to September, when river levels fall enough for wading approaches; sudden rain can raise rivers within hours.
Autumn
Colours reach the upper valleys in late September and the lowlands in October; the first snow falls on the ridges in October.
Winter
Heavy snow on the Tokachi side, clear and very cold weather on the plains; the range is visited only by experienced winter mountaineers and ski tourers.
Routes and trails
Poroshiri-dake via the Nukabira River
A two- to three-day route with a shuttle bus approach and many river crossings to the Poroshiri hut, then the summit via the ridge.
Apoi-dake
A day hike of 4 to 6 hours from the visitor centre through peridotite scrub and alpine flowers to the 810 m summit.
Satsunai-dake
A popular route on the Tokachi side following the Satsunai River to a summit with cirques on both sides.
Cape Erimo coastal walk
Short paths on the headland to viewpoints over the reefs and the seal colony.
Practical notes
- The park is reached by road from Obihiro (Tokachi side) or along the Hidaka coast from Tomakomai and Sapporo; public transport to trailheads is minimal.
- Most high routes involve river wading and pathless sections; rivers rise fast after rain, and several fatal drownings have occurred.
- Brown bears are common throughout the range; carry spray, store food properly and camp with care.
- Forest roads to trailheads are often closed after storm damage; check with local authorities and the Ministry of the Environment before setting out.
- Collecting plants on Apoi-dake and elsewhere is illegal; endemic species have been driven to near extinction by poaching.
Frequently asked questions
When did the park become a national park?
On 25 June 2024, as Japan's 35th national park. It grew out of the Hidaka-sanmyaku Erimo Quasi-National Park, designated in 1981, and was enlarged on the Tokachi side, which is why Tokachi was added to its name.
Why is it considered so wild?
No road crosses the southern range, there are very few mountain huts and many routes follow river valleys, requiring stream wading. Brown bears are widespread, and most peaks need multi-day trips with full self-sufficiency.
What is special about Mount Apoi?
Apoi-dake, only 810 m high, is made of peridotite from the Earth's mantle. The unusual rock keeps trees from growing, so some 80 alpine plant species, many of them endemic, flourish at low altitude; its flora is a Special Natural Monument.
What can be seen at Cape Erimo?
Reefs running far out to sea, a colony of Kuril harbour seals, and one of the windiest coasts in Japan. The surrounding hills were reforested by local fishermen from the 1950s after overgrazing and logging had turned them into sand desert.
Are there glaciers in the Hidaka mountains?
Not today, but glaciers during the last Ice Age carved cirques below the main peaks, such as the Nanatsu-numa cirque under Poroshiri-dake, the clearest glacial landforms in Hokkaido.
Related
Sources
- 1.日高山脈襟裳十勝国立公園 (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.Hidakasanmyaku-Erimo-Tokachi National Park (opens in a new tab) — Ministry of the Environment, Japan
- 4.アポイ岳ユネスコ世界ジオパーク (opens in a new tab) — 日本ジオパークネットワーク