Natural Features of Hiidenportti National Park 

Pond with a swampy beach. The rock walls and trees are around.


The Hiidenportti National Park gives an idea of what the wilderness at Korpi-Kainuu used to look like: Sparsely populated lands, low forested rocky areas and rugged mires.

Taking care of nature

Magnificent views from the edge of the gorge

Hiidenportti gorge takes visitors back in time. Some 1,900 million years ago elemental forces were unchained as some of the world’s oldest tectonic plates shifted. The bedrock was ripped open, creating a gorge with steep walls. 

Hikers have climbed up a steep stone wall. There are railings at the top of the wall. Pines spatter the landscape.

The ice sheet retreated at the end of the Ice Age around 11,000 years ago and revealed the gorge hidden underneath. The chilly waters of Sotkamo ice lake discharged into the fissure valley as raging rapids. When the edge of the ice sheet moved further, the channel gradually ran dry. 

This gorge serving as a gateway to the wildernesses of South Kainuu is today surrounded by low hills, boreal forests and aapa mires. Hiidenportti gorge stands in stark contrast to the forests around it. In places, there is a sheer drop of twenty metres down the rock faces of the gorge. The gorge walls frame dark ponds with narrow edges of wobbly mires. Impressive views open up from the cliff edges along the gorge, which is one kilometre in length. 

Hiidenportti divides waters

Hiidenportti gorge is a watershed. From here, waters flow northwest to the water system of Oulujoki River, and northeast along Porttijoki River towards Lake Ladoga. In the catchment area of Porttijoki River there are dozens of small, barren lakes and ponds with waters dyed brown by humus. Evidence of the way the bedrock shifted millions of years ago can be seen all along this river. Crags, bolder fields and narrow mires surround the shores of the small lakes.  

Water lilies grow in the pond water. Hay and Carex grow upright at the shore.

Porttijoki River was dredged and dammed for timber floating in the early 1900s. Since then, trees have fallen into small rivers and streams left in a natural state. The rapids are dotted with boulders and rocks, on which algae and fontinalis mosses grow. They shelter the larvae of such species as caddisflies, mayflies and stoneflies and many other organisms living on the bottom of water bodies.   

A river whorls downwards. The beaches are rocky, tree trunks are resting on the shoreline.

The white-throated dipper dives into the rapids to feed on these benthic organisms. Otters also feel at home in the small rivers. Perk, pike and roach occur naturally in the National Park’s waters, but no salmonids have made their way to Hiidenportti water system. 

The goblin-like great grey owl

When out skiing in Hiidenportti National Park in winter, you may see an impression in soft snow surrounded by marks made by large wings. This impression was left by a great grey owl, a bird of old conifer and mixed forests, hunting for a vole under the snow. The owl’s large facial disc works like a parabolic antenna, directing sound waves to the owl’s ears. 

A great gray owl is sitting on a branch and looks directly at the photographer.

The great grey owl is a large bird. It is about 65 to 70 cm tall, with a wing span of 135 to 160 cm. The great grey owl nests in abandoned roosts of other birds of prey or on top of broken deadwood stumps. It defends its offspring ferociously and may attack an intruder with its sharp claws, which is why the nest should not be approached. A great grey owl chick, the national park’s emblem, looks rather like a goblin. 

Other winged creatures in Hiidenportti 

Hiidenportti is home to many birds that live in old-growth forests. A lucky hiker may spot a rare red-flanked bluetail, which lives in Finland on the western margins of its range. The red-breasted flycatcher migrates all the way from India to nest in Hiidenportti. It prefers old, moist spruce woods and mixed forests with decaying stumps and fallen trees. The critically endangered willow tit lives in the National Park round the year, surviving over winter on insects it has stashed away in beard lichen. Using its dainty peak, the willow tit hacks a hollow in a decayed birch stump for its nest. 

The most common bird species in the park are the common chaffinch and willow warbler as well as the Eurasian siskin, spotted flycatcher and tree pipit. Dwellers of old mixed forests include the robin, goldcrest and wood warbler, whereas the northern goshawk and three-toed woodpecker prefer spruce woods. The inquisitive Siberian jay follows a hiker around. 

A siberian jay spreads its wings as it lifts off from a branch.

The National Park has few mire species, and such birds as the meadow pipit and western yellow wagtail are rarely seen here. The wood sandpiper, on the other hand, is a common species also in Hiidenportti. 

Hear the whispering of our wilderness

The National Park is a mosaic of mires and heaths. Heath forests cover about two thirds of its land area. The last major fellings in Portinsalo were carried out in the early 1900s. In earlier times, the forests had also been used for slash and burn farming and tar-burning. Over time, the forests have reverted to a natural state. The diverse range of tree species in the park comprises old silver and downy birches, goat willows, thick-barked pines, aspens, deadwood and chunky decaying wood. Most of the trees are aged between 110 and 170 years on average, while in places they are more than 200 years old. 

A small path leads through the old forest. Som trees have fallen, while other remain standing.

In Hiidenportti  National Park the hilltops are usually covered in pines, whereas spruces grow on the slopes. Some of the most spectacular old spruce forests in the park are found on the slopes of Urpovaara hill. The signposted trail from Urpovaara to Hiidenportti takes you through their shadowy depths. Mixed in with the large spruces there are magnificent aspens.

Only one area of herb-rich forest is found in the National Park. Its plant species include bearded wheatgrass, daphne, cinnamon rose and black baneberry. Plenty of birch forest can still be found in places on the slopes of Kovasinvaara hill, where slash and burn farming was still practised in the early 1900s. The vegetation on herb-rich slash-and-burn lands is lush and diverse.

Wild forest reindeer – a wanderer of lichen woodlands 

The wild forest reindeer, a close relative of the domesticated reindeer, was hunted to extinction in Finland in the early 1900s. A small population survived in the wildernesses of Russian Karelia, and several decades later, the wild forest reindeer started gradually spreading westwards. The first observations of its return to Finland were made on the eastern border of Kuhmo in Elimyssalo area in the late 1950s. From then on, the population started slowly recovering. 

The wild forest reindeer prefers quiet lichen woodlands in the winter and lush mires in the summer. In the spring they migrate east to their calving areas and summer pastures, and the herds disperse. In the autumn, the wild forest reindeer start regathering into herds and make their way westwards to their winter pastures. The range of their winter pastures has gradually expanded further west. Nowadays, wild forest reindeer can be spotted also in Hiidenportti National Park in the winter. 

Two Finnish forest reindeer with horns are walking on top of a frozen lake that is covered with snow.

The wild forest reindeer and the domesticated reindeer look very similar. Sometimes it is impossible to tell apart by their looks alone. The wild forest reindeer is usually bigger. Its legs are longer, and its antlers are narrower and bigger than a reindeer’s. The wild forest reindeer is darker in colour and more timid than a reindeer. A wild forest reindeer and a reindeer can breed and produce fertile offspring, but hybridisation reduces the genetically pure wild forest reindeer population.

Ruggedly beautiful mires

The mires in Hiidenportti are in their natural state. Confined by the varied topography, the open or flark ‘rimpi’ mires in the park are relatively small. The largest flark mires in Hiidenportti National Park are Kortesuo and Urposuo. The wettest parts of a flark mire, the rimpi-surfaces, are particularly valuable as habitat for species not encountered anywhere else. 

A flark marsh where many different hay species grow. Water is visible among the flark. In the background is a forest.

Spruce mires are found on stream banks, in narrow valleys with steep slopes and on forest edges. As a home for both mire and forest species, they have a high level of biodiversity. Sturdy decaying wood in spruce mires provides a habitat for many endangered species. Also lush spruce mires with ferns can be found near springs and streams. The most common mire type in the park is the dwarf shrub pine bog with marsh Labrador tea and pines. 

Wooden footpaths lead across a marsh towards a lake. The white flowers of Eriophorum latifolium stand out against the marsh.

The lushest growth sites in Hiidenportti are spring habitats, seepage areas and rich spruce-birch fens. Plant species found in grassy and rich fens include the early marsh orchid, broad-leaved cotton grass and eggleaf twayblade.  

Cassandra of the eastern taiga 

Cassandra, a plant in the heather family with small white flowers, blooms in the mires in the spring after the snow has melted. Kainuu is a stronghold of this plant, which is even more common here than the marsh Labrador tea. Cassandra is one of the mire species more common in the middle parts of Finland than further south or north. This continental species does not grow in Western Europe, and in the Nordic countries it only occurs in Finland as well as in Torniojoki River valley in Sweden. In Swedish, this plant is thus called finnmyrten, the Finnish myrtle.    

The inflorescence of a Chamaedaphne calyculata hang down from the trunk. An insect is sicking nectar from the inflorescence.

The small heather has adapted to cold winters and hot summers and does not like long, mild autumns. In the winter, cassandra allows its leaves to hang, and they turn a coppery red. The leaves stand up and regain their olive green colour in the spring. The plant drops its previous year’s leaves during the flowering season, as they are replaced by fresh ones. The leathery leaves have a strong odor.  

Hiisi’s cattle

Meetings with large carnivores or other large mammals in the National Park are extremely rare. Their acute senses allow them to escape before they are spotted by humans. An observant hiker may find their tracks, however. Occasionally, you might see the tracks of a wolverine or a lynx on the spring snow. A pile of hair may be the only thing left of a wild forest reindeer or an elk caught by a wolf pack. Once the wolves have had their fill, a wolverine has carried the bones to its own food stores.  

A bear walks in a marsh among trees and Eriophorum latifolium.

In the spring, you might find something resembling a human footprint in the wet soil on the side of the road – left there by the back paw of a bear. In the autumn, a large pile of bear droppings full of blueberry and lingonberry skins and leaves may be seen beside a path. Sometimes you also come across an anthill scattered by a bear. 

For more information about large carnivores, visit

Heritage landscapes are being maintained in the meadows of wilderness farms

A hiker approaching Kovasinvaara hill first walks through a light-filled birch grove and soon reaches a meadow. Kovasinvaara farm was inhabited from the 1700s until 1949. The dwellers of the wilderness farm scraped a living from slash and burn farming, cattle husbandry and growing crops in a small patch of a field. These traditional modes of land use created many species-rich habitats in Kovasinvaara, including mesic meadows, wooded pastures and slash-and-burn meadows. These habitats are today known as traditional rural biotopes. Kovasinvaara is a traditional rural biotope of national value regularly managed by Parks & Wildlife Finland by mowing and clearing. 

Image of a summer meadow bounded by birches. The grass and flowering meadow plants grow tall in the meadow.

A small-scale slashing and burning operation took place in Kovasinvaara over an area of some four ares in 2011. A few years earlier, the birches in this area had been felled and left to dry. When the area was burned, birch trunks were rolled along as the fire moved on to ensure that the thick heath turf layer would be scorched to ashes as effectively as possible. Turnips were sewed in the burnt area by the traditional method of spitting the seeds out around midsummer. In July, the burnt area was harrowed by using a traditional, horse-drawn implement. Rye was sown in the area on 25 July. In the following year, the rye was cut with sickles, collected into sheaves and stooked. The four ares produced four stooks. In the era of slash-and-burn farming, at least 100 kg of rye per person were needed to survive over winter.

A spectrum of species in deadwood

The coniferous forests of Hiidenportti have provided habitats for organisms adapted to using decaying wood, or other species living in decaying wood, as their habitat or food source. In their natural state, boreal forests offer plenty of deadwood, and wood decomposes slowly. Outside protected areas, decaying wood has become scant, which has made species dependent on it ‘demanding’.

A tree has fallen in a coniferous forest and is slowly decomposing under some mosses.

The Cephalozia macounii moss is a liverwort growing on decaying wood. This tiny species does not accept any old stump as its growth medium, as the decaying wood must be sturdy and located in a moist old-growth forest where continuous availability of decaying wood is guaranteed. Other mosses also like to grow on the surface of decaying wood, and when the competition for living space becomes tough, Cephalozia macounii moss retreats to the butt end or lower surface of the trunk, to which other mosses may find it more difficult to cling. 

Agathidium pulchellum is a golden yellow beetle a few millimetres in length, and it only lives in the best old spruce forests with decaying wood. Some of this forest type, which usually contains plenty of aspens, has been preserved in Hiidenportti National Park. The Finnish name of this beetle (‘jewel ball’) refers not only to its pretty rounded back but also the fact that when disturbed, the beetle rolls itself into a ball. This beetle species is rare, and its living habits are not particularly well known, but it is known to be dependent on Trichia decipiens slime mold, which lives in decaying wood and forest litter.

A Agathidium pulchellum seen from above. It has a glossy convex back and forward-pointing horns.

Such mosses and beetles are examples of species at risk of disappearing. This is why the Nature Conservation Act and Decree list them as species requiring particular protection. They are managed by collecting data on and monitoring changes in their population sizes and habitats. Where necessary, their habitats are managed to ensure the preservation of these species.

Hiidenportti National Park

  • Established 1982
  • Area 45 km²

Hiidenportti's drawn national park emblem. The oval emblem shows a great grey owl and some spruce twigs. Text wraps around the outer edges of the emblem.

The emblem of Hiidenportti National Park is Great Grey Owl

Publications of Hiidenportti National Park

Publications of Hiidenportti National Park (