Thawing permafrost threatens nearly half of Swiss mountain huts

Sixty-five of the Swiss Alpine Club’s 152 huts sit in areas potentially threatened by thawing permafrost. The changing ground is already forcing the club to relocate buildings and invest in new facilities and protective work across the Alps.

The collapse of the old Mutthorn hut in the Bernese Oberland brought the risk into sharp focus. Closed since 2021, the hut had been damaged by widening cracks and faced the prospect of collapse. The SAC dismantled it in summer 2025. Its replacement now stands less than a kilometre away, on more stable ground and in a location less exposed to avalanches.

The shift affects more than buildings. Rockfalls, mudslides and ground movement are making routes to some huts more hazardous. For climbers and hikers, a familiar mountain refuge can depend on terrain that is changing beneath it.

Permafrost binds rock together, and its thaw can loosen the slopes above a hut. As ice within the ground melts, water enters cracks and weakens the surrounding rock. That process has been visible above Mutthorn, where a fissure measured 70 centimetres across in 2007 and later widened to nearly 1.5 metres.

Nils Hählen, head of natural hazards for canton Bern, said the timing and scale of falling rock cannot be predicted. He warned that collapse was certain. His assessment captures the challenge facing the SAC and local authorities: they must make decisions about buildings and access routes while the ground itself is shifting.

The threat extends beyond Mutthorn. The SAC says 65 huts are in areas potentially exposed to permafrost thaw. Routes can also be affected by rockfalls, mudslides and ground movement, adding another layer of risk for people travelling through the high mountains.

The replacement Mutthorn hut cost CHF 4 million, after the old building’s dismantling added another CHF 400,000. The new hut was inaugurated in June 2026 on more stable ground, less than a kilometre from the original site and in a position less exposed to avalanches. Nearly 700 helicopter flights were needed for the project.

The cost drew criticism within the SAC, although two-thirds of members of the local section approved the project. The decision reflects the scale of work required when a hut can no longer safely remain where it stands. The club’s choices may include relocating buildings, simplifying them or making some mobile.

The Trift hut offers another example. An avalanche destroyed it in 2021 after nearby glacier melt had altered the terrain and expanded potential avalanche release zones. The replacement was moved one kilometre and cost CHF 5 million. These projects show how changing mountain conditions can demand both new sites and major construction budgets.