THREE COUNTRIES, ONE LOOP: THE HISTORY OF UTMB

In August 2003, 722 runners left Chamonix to run a loop around Mont Blanc. They would cross three countries, climb roughly 10,000 meters of elevation, and cover 171 kilometers of alpine trail. Only 67 of them finished. The Ultra-Trail du Mont-Blanc had announced itself the way the mountains always do: by breaking most of the people who showed up.

Two decades later, UTMB is the most prestigious race in trail ultrarunning. The event has grown from a single race into a week-long festival, spawned a global qualifying series, and attracted corporate investment that has reshaped the economics of the sport. Whether that growth has been entirely good for trail running depends on who you ask. What is not debatable is that UTMB changed everything.

The Idea

The concept was simple and old. The Tour du Mont Blanc is one of Europe's classic long-distance hiking routes, a circuit around western Europe's highest peak that passes through France, Italy, and Switzerland. Hikers typically complete it in 7-10 days. The question was whether runners could do it in a single push.

Catherine and Michel Poletti, both trail runners from the Chamonix valley, organized the first edition. The route followed the TMB hiking trail with modifications for safety and logistics. Runners started and finished in Chamonix, heading counter-clockwise through Courmayeur, Italy, and Champex-Lac, Switzerland, before returning over the final cols to the Arve valley.

The 2003 race was won by Dawa Sherpa of Nepal in 20:55:42. Krissy Moehl of the United States won the women's race in 27:22:34. The attrition rate, over 90 percent, signaled that this was a different kind of event. This was not a road ultra where the distance was the challenge. Here the mountains, the weather, the altitude, and the technical terrain combined to create something that tested every dimension of an endurance athlete.

The Champions

UTMB's winners list reads like a hall of fame for the sport. Kilian Jornet, the Spanish mountain runner widely regarded as the greatest trail athlete ever, won four times (2008, 2009, 2011, 2022). Francois D'Haene of France matched that total with victories in 2012, 2014, 2017, and 2021. Xavier Thevenard, also French, won three times (2013, 2015, 2018).

The women's race has been equally compelling. Lizzy Hawker of Great Britain won five times between 2005 and 2012, establishing a standard of dominance that seemed untouchable. Then Courtney Dauwalter arrived.

Dauwalter, from the United States, won UTMB in 2019, 2021, and 2023. Her 2021 performance was a landmark: she finished in 22:30:55, setting a women's course record and placing seventh overall, ahead of hundreds of elite male competitors — a mark that stood until Katie Schide ran 22:09:31 in 2024, part of a record progression that has accelerated sharply in the past five years. Dauwalter's ability to compete at the sharp end of the overall race, not just the women's field, challenged assumptions about the limits of female ultra performance.

Course Records and the Speed Era

The men's course record belongs to D'Haene, who ran 19:01:54 in 2017 on the pre-2023 course. Jornet's 2022 winning time of 19:49:30 came on a modified route and is sometimes cited as the record depending on course measurement.

The speed at the front of UTMB has increased dramatically since the early editions. What was once a survival event has become a race at the pointy end, with top contenders running significant portions of the course at paces that would be respectable in a road marathon. The back of the pack still treats it as an adventure. That gap between front and back is wider at UTMB than at almost any other sporting event in the world.

The UTMB World Series

In 2022, UTMB partnered with the IRONMAN Group to launch the UTMB World Series, a global circuit of qualifying races. The series replaced the old qualifying points system with a standardized index that ranks runners based on performances at designated events worldwide.

The expansion was controversial. Purists argued that UTMB was commercializing a sport built on self-reliance and community. The partnership with IRONMAN, a corporation known for aggressive monetization of endurance events, fueled concerns about entry fees, sponsorship conflicts, and the loss of trail running's independent spirit.

Proponents countered that the series brought structure and legitimacy to a sport that had outgrown its informal roots. The qualifying system gave runners around the world a clear pathway to Chamonix. Prize money increased. Media coverage expanded. Whether those were net positives remained a matter of debate.

Weather, DNFs, and Drama

UTMB's defining characteristic is its unpredictability. The race takes place in late August, when alpine weather can shift from warm sunshine to freezing rain in hours. Runners carry mandatory kit including waterproof layers, headlamps, and emergency supplies. Even so, the DNF rate regularly exceeds 40 percent.

The 2010 race was cancelled mid-event due to severe weather, with runners evacuated from high mountain sections. Other editions have seen snow at altitude, thick fog that reduced visibility to meters, and mud that turned technical descents into controlled slides.

This volatility is part of the appeal. UTMB is one of the few major endurance events where the outcome is genuinely uncertain until the final hours. Favorites drop out. Unknown runners emerge from the fog. The mountain does not care about your qualifying time or your sponsor.

The Course Today

The current UTMB route covers approximately 171 kilometers with around 10,000 meters of positive elevation gain. Runners start in Chamonix at 6 PM on Friday and the fastest finish Saturday afternoon. The cutoff time is 46 hours and 30 minutes.

Key sections include the climb to Col de la Forclaz, the descent into Courmayeur (where crews can meet runners), the long climb over Grand Col Ferret on the Italian-Swiss border, and the final ascent to the Bovine and La Flegere before the descent into Chamonix.

The event week includes several other races: CCC (101km), TDS (145km), OCC (56km), and others. Together they draw more than 10,000 runners to the Chamonix valley, making UTMB week the largest trail running gathering in the world.

What UTMB Built

From 67 finishers in 2003 to 10,000 participants across the event week, UTMB's growth has been extraordinary. The race created a template for elite trail ultrarunning: a signature event with global qualifying, professional media production, and prize money that allows the sport's best athletes to compete as professionals.

Whether the sport is better for it depends on what you value. The mountains around Mont Blanc have not changed. The weather is still capricious, the climbs still relentless, the distance still almost absurd. What has changed is everything around the race: the money, the media, the qualifying system, the corporate structure. The loop around Mont Blanc remains the same 171 kilometers it was in 2003. Everything else has been transformed.