The world’s biggest trail running event is about to get underway in Chamonix, France, and you can tune in to the live action from the French Alps on your laptop or phone.
For years, the Ultra-Trail du Mont-Blanc (UTMB) has been the most celebrated and most competitive ultra-distance trail running race on the planet. The race starts in Chamonix and sends runners on a 108-mile (172K) counterclockwise journey around the Mont Blanc Massif through parts of Italy and Switzerland before finishing back in Chamonix. The route goes up and over 10 mountain passes and includes about 33,000 feet of vertical gain and loss.
What began as a singular race in 2003 has turned into a festival of races and events that attracts more than 12,000 participants and thousands more spectators. (There are about 550 total U.S. runners entered in the races, including what is believed to be a record 191 the main UTMB race, 140 in the CCC 100K, and 121 in the OCC 50K.) In addition to running races, there are dozens of fun runs, shoe launches and demos, speakers panels, film premieres, vertical challenges, and running industry events, making it the busiest week of the year in Chamonix.
The UTMB race, which begins Friday (11:45 a.m. ET), is still the most notable race and one of three championship races of the 60-race UTMB World Series, World Mountain and Trail Running Championships OCC 50K (2:15 a.m. ET) and CCC 100K (3 a.m. ET). Other races during the week include Monday’s MCC 40K, TDS 148K, PTL 300K, Tuesday’s ETC 15K, and YCC youth races. The course of each race is vastly different with its own challenging features and volume of elevation change.
“Chamonix is definitely a one-of-a-kind place,” said Jason Schlarb, 47, the 2016 Hardrock 100 co-champion from Durango, Colorado, who has finished UTMB four times, including a fourth-place overall finish in 2014. “I’ve had good races here and bad races here, but the reason I am back is because UTMB is the big show, it’s where the competition is. It’s the race everybody talks about.”
Races & Places
Each of the races can be followed via live tracking, while the championship races (OCC, CCC, UTMB) can be watched via livestream on the UTMB website or on YouTube. The around-the-clock live coverage includes expert commentary in multiple languages with video coverage provided by drones, e-mountain bikes, and runner follow cams.
Western States 100
Women
In the marquee UTMB event, American Courtney Dauwalter once again headlines the women’s race. The 40-year-old Leadville, Colorado, resident has won the event three times (2019, 2021, 2023), trailing only British runner Lizzy Hawker (2005, 2008, 2010-2012) for the most wins among women. American women have won the race 10 times, the most among any nationality.
Although Dauwalter has been nearly unbeatable since 2018, she suffered a rare DNF at the Cocodona 250 race in Arizona in May—even though she was leading at the 108-mile mark when she dropped out. She’s won 25 of the past 26 races she’s finished dating back to 2020, with the lone exception of the 2023 Javelina Jundred 100K race that she ran with her mom. In March, Dauwalter won a trail marathon race in March in Colorado and 50K race in Arizona, and then won the 74.5-mile Lavaredo Ultra Trail race in Italy in late June.
While the trail running world was hoping to see Dauwalter face off with two-time UTMB champion Katie Schide, an American who lives full-time in France, the 2022 and 2024 champion has opted instead to focus on the 2025 while the championship races OCC, CCC, UTMB can be watched via livestream on the next month in Spain, especially given that she just won the Hardrock 100 in course-record time on July 12.
Instead, Dauwalter’s primary challengers will likely be American Abby Hall (Flagstaff, Arizona), New Zealand’s Ruth Croft, Zimbabwe’s Emily Hawgood, Germany’s Katharina Hartmuth, and American Heather Jackson (Bend, Oregon). A year ago, Hall, 35, finished 31st among women in UTMB about 16 months after suffering a devastating knee and leg injury. But her real comeback moment came in June, when she won the Western States 100 in Auburn, California—the biggest win of her career. Prior to her injury, she posted three top-10 finishes in the CCC 100K, including a runner-up finish in 2021.
“I feel like UTMB, you kind of earn it during the race,” Hall said. “The training for UTMB feels a little bit more universally fun versus, say, the training for Western States, which I think feels a little less glamorous than the thing itself. It feels like it’s a little flipped for UTMB, where the training’s really fun. You’re doing these long days in the mountains, and then you get out there and you kind of have to fight for it and earn it during the race.”
Croft, 36, who has already won the CCC 100K (2015) and Western States (2022), placed second in UTMB last year behind Schide. Hawgood, 31, has been a top-10 finisher at Western States each of the past five years and placed sixth in each of the last two UTMB races. And Hartmuth, 30, finished third in the Hardrock 100 in Colorado for the second year in a row and also finished second to Dauwalter in the 2023 UTMB.
Jackson, 42, meanwhile, is a former pro triathlete who has transitioned into a new pro career as a gravel bike racer and ultrarunner. Although she DNF’ed at Western States this year, she placed fifth in the CCC 100K in Chamonix last year and has also won the 350-mile Unbound Gravel XL on May 30 in Kansas.
Other top Americans include Alyssa Clark, 32, a two-time winner of Hawaii’s HURT 100 who was 11th at UTMB last year; Lindsey Dwyer, 34, who finished second at the Cocodona 250 in May; Stephanie Howe, 42, the 2014 Western States 100 champion who has been living near Chamonix the past three years; and Lauren Puretz, 42, who is racing overseas for the first time.
Men
Last year, Vincent Bouillard, a full-time shoe materials science engineer for Hoka, pulled off a surprise UTMB win in the fourth-fastest time ever run on the course. He’s not returning to the race this year, and neither is 2023 champion Jim Walmsley, who became the first American to win UTMB, or 2022 champion Kilian Jornet of Spain, so this year’s race is wide open and could see a first-time champion crowned.
Walmsley is running the OCC 50K, in part, so he can remain fresh to compete in the September 25-28 while the championship races OCC, CCC, UTMB can be watched via livestream on the in Spain, while Bouillard is skipping the UTMB week of races entirely to focus on next month’s world championships. Jornet just finished third at the Western States 100 and is planning to return to the U.S. to summit all of the 14,000-foot peaks in the American West in September.
That said, the men’s field is chock-full of experienced international competitors, led by American Hayden Hawks, France’s Ludovic Pommeret, New Zealand’s Daniel Jones, China’s Ji Duo, and British runners Tom Evans and Jonathan Albon.
Hawks, 34, is a two-time CCC 100K winner (2017, 2024) who has also twice finished on the podium at Western States. Pommeret, 50, the 2016 UTMB champion, won his second straight Hardrock 100 title in July and last year placed fifth in UTMB. Although the 33-year-old Evans has been battling injuries the past few years, he has a Western States 100 victory (2023) and a CCC 100K title (2018 ) under his belt. Albon, 36, won CCC in 2023 and OCC in 2021, and also has 14 obstacle course racing world championships to his credit. Jones, 34, is a former 2:16 marathoner who has placed among the top five at the past three Western States 100 races, while Duo, 33, has won numerous races in China and was 13th in UTMB in 2023.
Other top Americans include Rod Farvard, who finished second to Walmsley in the 2024 Western States 100; Jeff Mogavero, 31, who placed fourth at Western States in late June; and Ben Dhiman, 33, who has lived in the French Pyrenees and raced internationally for the past four years.
Race Schedule and Course Information
Monday, August 25
- PTL, Advertisement - Continue Reading Below
- MCC, Nutrition - Weight Loss
- TDS, How to Avoid Injuries
Tuesday, August 26
- ETC, How to Stream UTMB
- YCC, Courmayeur, Italy, 9.3 miles, 3,940 feet of elevation gain, 4 hours, 30 minutes cutoff time (also 5-mile and 2.5 mile races for younger age-groups)
Thursday, August 28
- OCC, Orsières, Switzerland, 35.4 miles, 11,482 feet of elevation gain, 14 hours, 30 minutes cutoff time
Friday, August 29
- CCC, The Mind-Boggling Stats of the 2025 Leadville 100
- UTMB, World Mountain and Trail Running Championships
Brian Metzler is a Boulder, Colorado, writer and editor whose work has appeared in Runner’s World, Sports Illustrated, ESPN, Outside, Trail Runner, while the championship races OCC, CCC, UTMB can be watched via livestream on the, and Red Bulletin. He’s a former walk-on college middle-distance runner who has transitioned to trail running and pack burro racing in Colorado.
