UTMB faces scrutiny over scale and environmental impact

The Ultra-Trail du Mont-Blanc (UTMB), a premier global trail running event spanning France, Italy, and Switzerland, is facing growing scrutiny regarding its scale and environmental impact. While the sport is seeing rapid growth in France—with a 69% increase in trail running activities over the last decade—local officials are expressing concerns about the event's footprint.

Chamonix Mayor François-Xavier Laffin has called for a need to ‘slow the machine,’ noting that the event's size has outpaced the territory's capacity. Similarly, Jean-Marc Peillex, the mayor of Saint-Gervais-les-Bains, has advocated for limiting access to the Mont Blanc route by 2027, proposing mandatory reservations for refuges or bivouac zones to manage overcrowding and environmental protection.

The UTMB organizers have acknowledged that the event's future is tied to the cooperation of local authorities, stating that a lack of support from municipalities could put the event at risk. This tension comes alongside environmental challenges in the Alps, where record heat in 2026 has led to increased rockfalls and permafrost degradation, complicating mountain safety.