UTMB Mont-Blanc has folded sustainability directly into its 2026 lottery rules in the most overt way any of the World Marathon Majors or trail majors has yet attempted. Runners who commit to reaching the Chamonix valley by lower-carbon, car-free transport — rail, coach or shared bus — will see their lottery odds boosted by 30 per cent, and every successful entrant will pay a mandatory carbon contribution scaled to the round-trip emissions of their travel. The two changes were confirmed in the registration conditions published this spring alongside refinements to the Running Stones system.
The mobility boost is engineered as a behavioural lever rather than a discount. Eligibility requires runners to declare their travel intent at registration, with verification at bib pickup; the bonus stacks on top of any Running Stones held, meaning a runner with a single 2025 stone who books the train from Geneva can effectively double their entry weighting against a stone-equivalent driver. Race director Catherine Poletti has framed the change as a response to repeated audits showing that participant travel accounts for the overwhelming majority of the event's carbon footprint, dwarfing course logistics, hospitality and waste.
The carbon contribution is the second half of the equation. Runners enter their travel plans at registration and are billed a tiered fee tied to the calculated emissions of their journey, with proceeds ring-fenced for restoration projects in the Mont-Blanc massif and partner trail networks. The exact tariffs are still being finalised but UTMB has indicated they will sit in the low tens of euros for European entrants travelling overland and rise to a meaningfully higher tier for transcontinental flyers, who account for the largest single share of the event's footprint.
The Running Stones rules have been tightened in parallel. Stones still require finishing a UTMB World Series qualifier and remain valid for two years from the date of issue; runners who go more than 24 months without earning one will see their entire balance go inactive, although a single new finish reactivates the lot. UTMB has also confirmed that the OCC, ETC and MCC distances will move to a pure lottery for 2026, removing the Stones requirement for shorter distances and opening up the most accessible race tier to a broader entry pool.
For elite and competitive amateur runners chasing 2026 spots, the practical advice is simple: book the train, declare it, and treat the carbon contribution as a fixed entry cost. For organisers watching from other major races — Western States, Comrades, the road majors — UTMB has now planted a flag that turns sustainability talking points into entry mechanics. Whether the rest of the calendar follows is the next thing to watch.