Rob Krar runs through Twin Lakes aid station on his way to winning the 2018 Leadville 100. Photo Mark McCaslin

What’s Up in Ultra This Weekend — August 16, 2025

Drew Dinan
Drew Dinan

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In this week’s What’s Up in Ultra, we feature ultramarathons in Colorado, Michigan, West Virginia, New York and British Columbia, Canada. Be sure to check out all 39 upcoming races on the UltraRunning Magazine race calendar. If you’re a race director and would like your event to be featured in the calendar, register here.

Featured: Leadville Trail 100 (Leadville, CO)

The Leadville Trail 100, aka the “Race Across the Sky,” returns to the historic mining town of Leadville, Colorado, for its 42nd season. The iconic 100-mile ultramarathon takes runners on an out-and-back course through the Colorado Rocky Mountains where they’ll have to battle challenging terrain, thin air (the racecourse never dips below 9,200 feet above sea level), and more than 18,000 feet of climbs and descents, including two summits of Hope Pass at 12,600 feet: once at mile 43.5 and again at mile 56.5. Entrants will have 30 hours to complete the race to earn their Leadville buckle, with sub-25-hour finishers taking home the coveted “big” buckle. Live results here. Read more.

Other West Events:

Pacific

Mountain

Featured: Marquette Trail 50 (Marquette, MI)

Established in 2009, the Marquette Trail 50 (50k and 50-mile ultramarathons) is held near the shores of Lake Superior and showcases some of the best trails in Michigan’s Upper Peninsula. Both the 50k and 50-mile races begin on Saturday at 5:30 a.m. at the Forestville Trailhead. On course, runners can expect moderate to difficult terrain with a few technical sections. The 50k runners will have 12 hours to tackle 3,237 feet of elevation gain over one 11-mile “small loop,” and one 20-mile “big loop.” The 50-milers will have 15 hours to complete their race, which features 5,520 feet of gain and loss spread over one small loop and two big loops (run once in each direction). Read more.

Other Midwest Events:

Featured: Miner’s Lady 8-Hour Race (Harper’s Ferry, West Virginia)

The Miner’s Lady 8-Hour Endurance Race is a fixed-time ultramarathon held in Harper’s Ferry, West Virginia. Race entrants will start at 6 a.m. Saturday at Rolling Ridge Conservancy and see how many 10k laps they can complete before 2 p.m. The course winds through the stunning Blue Ridge Mountains and along the Shenandoah River and includes mostly runnable singletrack trails and crushed gravel paths, several water crossings and 850 feet of elevation gain per lap. Each year, the race celebrates regional artistry by commissioning handcrafted prizes, with this year’s top performers receiving beautiful locally made coffee mugs. Runners are encouraged to set a goal of running at least three laps. Read more.

Other South Events:

Southwest

Southeast

Featured: Twisted Branch Trail Run (Naples, New York)

The 11th annual Twisted Branch Trail Run 100k race begins at 4 a.m. on  Saturday at Ontario County Park in Naples, New York. Participants will have 20 hours to complete a point-to-point course through the breathtaking Finger Lakes region to earn their 2026 Western States qualifiers. Along the way, they’ll follow the historic Bristol Hills Branch Trail, where they’ll have to navigate unforgiving terrain and over 10,000 feet of elevation gain and 11,000 feet of loss. Twisted Branch has become a favorite of ultrarunners for its scenic course (95% singletrack trails), old-school trail running vibe, 11 great aid stations and some of the best volunteers you’ll find. Runners are welcome to camp for free at the start and at the finish line at the Hammondsport Fire Hall grounds. Read more.

Other Northeast Events:

Featured: Squamish 50 (Squamish, BC)

The 13th edition of the Squamish 50 (50-mile and 50k ultra distances) kicks off this weekend in Squamish, British Columbia. Known for its extremely challenging course, welcoming community and stunning natural scenery, Squamish 50 has grown to be one of the largest and most competitive ultramarathons in North America. The 50-milers will set off at 5 a.m. on Saturday from Junction Park in downtown Squamish before heading out to the rugged mountain trails that surround the city as they attempt to conquer over 3,400 meters of elevation gain and loss in under 17 hours. The top three women’s and men’s 50-mile finishers will share a $6,500 prize purse, with an additional $1,000 bonus for anyone who breaks the course record. The 50k runners will begin at 6:15 a.m. on Sunday and have 11.5 hours to navigate 2,500 meters of ascent and 2,750 meters of descent. Runners who complete both races will receive a 50/50 hat. Live weekend race coverage here. Read more.

Other Events in Canada and Mexico:

Email corys@ultrarunning with questions about adding your event to the UltraRunning Magazine calendar.

Drew Dinan traded the tropics of the Florida Keys for the trails of Bend, OR. Once living the Jimmy Buffett lifestyle, working on fishing boats and owning only a single pair of flip flops, he now has way too many running shoes in his closet and never hears the end of it from his loving wife. He is on a constant quest to find the best happy hours, likes to complain when it’s cold outside, and one day hopes to travel the country writing reviews on chicken wings.

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