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Nov 05, 2026

Korouoma ice falls: how the canyon’s waterfalls freeze each winter

Every winter, the rock walls of the Korouoma canyon in southern Lapland turn into columns and curtains of ice. Guests on our Korouoma Frozen Waterfalls Hike often ask the same question when they first see them: where does all that water come from, in a place where everything else is frozen?

This article answers that question using the information published by Metsähallitus, Parks & Wildlife Finland, which manages the Korouoma Nature Reserve. At the end we explain how the ice falls show up on our own tour.

The short answer: Korouoma is a roughly 30 km long fracture valley in the municipality of Posio. According to Metsähallitus, small streams cascade down its steep cliff faces, and in winter they freeze into icy waterfalls that stay frozen until late spring. The largest, Ruskea virta, is about 35–60 metres high.

At a glance

• From: 139 €
• Experience type: Nature tour
• Duration: 6 hours
• Difficulty: Challenging
• Book in Advance: Cut off: 3 hours before start time
• Included: A Tour Guide in English (other languages available on request: (Spanish, Portuguese, French, Italian, German & Finnish. PLEASE NOTE LIMITED AVAILABILITY FOR OTHER LANGUAGES). If another language is required. Please send us an email or WhatsApp after booking.); Winter clothing (Adult & Child size), overalls, boots, gloves, socks; Ice grippers for the shoes; Local berry juice and light snacks; Information about the Nature Reserve area; Pick-ups and drop-offs are included in the price in 10 km radius from Rovaniemi city center; Photos taken with your own device; Air conditioned car
• Cancellation: Free cancellation 24 hours before the activity. We will charge a cancellation fee of 100% if booking is cancelled less than 24 hours before the activity.
• Accessibility: Not wheelchair accessible; Not stroller accessible

A canyon made by a crack in the bedrock

Korouoma is not a river valley in the usual sense. Metsähallitus describes it as a 30-kilometre-long fracture valley running from northwest to southeast, part of a fracture zone in the bedrock that is hundreds of millions of years old. The bedrock is mostly coarse red granite, with gneissose granite in places and mica schist and quartzite in the southeastern part.

The result is a gorge that is 200 to 500 metres wide and, at its deepest, approximately 100–130 metres deep. Its cliff faces are tens of metres high and extremely steep – exactly the kind of walls on which water can freeze into vertical ice.

How the ice falls form

The explanation given by Metsähallitus is simple: small streams cascade down the cliff faces, and during winter they freeze into icy waterfalls. Once frozen, they stay frozen until late spring.

Because the ice is built by running water, how much ice forms depends on how much water is flowing when the frost arrives. The reserve’s own descriptions of individual icefalls show this clearly. At Revontuliputous, the ice is often flaky and thin because the water usually only runs in late autumn. The same is said of Jaska Jokunen, where the ice is thin and flaky in most years. Onnekas forms only infrequently, and Tuulen tie – a wall of thin, mostly vertical ice fingers – is not suitable for climbing every winter.

In other words, no two winters look exactly the same in Korouoma. The canyon’s own microclimate plays a part too: Metsähallitus notes that its climate differs noticeably from the surrounding area, with sunnier, warmer northeastern slopes and cooler southern and southwestern slopes.

The best-known icefalls, in figures

The figures below are the approximate dimensions published for Korouoma’s named icefalls:

• Ruskea virta (Brown River) – about 35–60 m high and 40 m wide; Korouoma’s largest and highest icefall.
• Mammuttiputous (Mammoth Fall) – about 35–50 m high and 40 m wide; one of the most popular climbing spots in Korouoma.
• Onnekas (Lucky One) – about 50 m high, about 100 m upstream along the River Korojoki from Mammuttiputous; forms infrequently.
• Jaska Jokunen (Charlie Brown) – about 50 m high and 20–60 m wide.
• Revontuliputous (Northern Light Fall) – about 40 m high and 5–10 m wide.
• Tuulen tie (Winds Way) – about 40 m high and 80–100 m wide.

Why ice climbers come here

Steep walls, reliable frost and water running down the rock make Korouoma one of the places in Finland that ice climbers seek out. Metsähallitus describes the reserve as offering some of the finest ice-climbing destinations in Finland in winter, and the steepness figures for the icefalls – many between 80 and 90 degrees – explain why.

Our tour is a hike, not a climbing course. You walk to the ice and look up at it; if climbers are on the falls that day, you may see them at work.

Life in the canyon

The canyon is more than ice. Korouoma’s landscapes range from herb-rich groves to old-growth forests and aapa mires. Metsähallitus lists 62 bird species in the area and 78 species of shelf fungi, and the canyon’s mix of cooler and warmer slopes lets northern plants such as alpine saxifrage grow close to more southern species like male fern.

In winter much of this is under snow, but the old forest and the silence along the valley floor are a large part of why a day here feels so different from a day in town.

How this shows up on our tours

On the Korouoma Frozen Waterfalls Hike (from 139 €, 6 hours) we pick you up within 10 km of Rovaniemi city centre and drive you to the reserve in an air-conditioned vehicle. According to the tour’s FAQ, the activity starts at 9:00, and transfers to and from your pick-up point come on top of the 6 hours.

We provide winter clothing (overalls, boots, gloves and socks), ice grippers for your shoes, and local berry juice with light snacks. Your guide tells you about the nature reserve along the way. The tour is listed as challenging; the FAQ explains that the hike is done slowly with plenty of stops, but it is not recommended for people with mobility challenges or serious medical conditions.

If you would rather go with only your own group, we also run the Private Korouoma Frozen Waterfalls Hike. More of our winter nature tours are on the nature & culture tours page, and our post on ruska in Rovaniemi covers what we run in autumn before the snow.

Before you go

Because the ice depends on the winter’s water and frost, the falls look different from one year to the next – that is part of their appeal. The hike runs in winter conditions, so dress in the clothing we provide and tell us when booking if anyone in your group has concerns about walking on snow and ice. The tour may be cancelled in extreme weather. If photographing the ice matters most to you, our post on photography tours in Rovaniemi explains how we plan our photo-focused outings.

Frequently asked questions

Where is Korouoma?

Korouoma Nature Reserve is in southern Lapland, in the municipality of Posio. It is managed by Metsähallitus, Parks & Wildlife Finland.

How do the Korouoma ice falls form?

Small streams cascade down the canyon’s steep cliff faces and freeze into icefalls in winter. According to Metsähallitus, they stay frozen until late spring.

How high are the frozen waterfalls?

The largest, Ruskea virta, is about 35–60 metres high. Several others, such as Mammuttiputous and Jaska Jokunen, are roughly 40–50 metres.

Are the ice falls the same every winter?

No. The amount and quality of ice depends on how much water runs down the rock before it freezes; some falls form only in some winters.

Is ice climbing part of the StayLapland hike?

No. Our Korouoma Frozen Waterfalls Hike is a guided walk to see the icefalls; ice climbing is not included.

What is included in the Korouoma hike?

Pick-up within 10 km of Rovaniemi city centre, an English-speaking guide, winter clothing, ice grippers for your shoes, local berry juice and light snacks.

Ready to book?

You may also like

• Private Korouoma Frozen Waterfalls Hike — from 1190 €, 6 hours

Sources

• Korouoma Nature Reserve – Metsähallitus (Nationalparks.fi)
• Nature of Korouoma – Metsähallitus (Nationalparks.fi)
• Sights in Korouoma Nature Reserve – Metsähallitus (Nationalparks.fi)
• Korouoma – Luontoon.fi (Metsähallitus)