• Top 10 in America USA Today 2024, 2025, 2026
  • #2 Fastest Growing Race in US - RunSignUp
  • Best Fall Marathons - Runners World
  • Top 10 in America USA Today
  • #2 Fastest Growing Race in US - RunSignUp
  • Best Fall Marathons - Runners World
  • Top 10 in America USA Today
  • #2 Fastest Growing Race in US - RunSignUp
  • Best Fall Marathons - Runners World
  • Top 10 in America USA Today
  • #2 Fastest Growing Race in US - RunSignUp
  • Best Fall Marathons - Runners World
Register
9.27.26

BOULDER MARATHON

COLORADO’S PREMIER FALL RACE WEEKEND

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WHY BOULDERTHON?

A boutique marathon experience with big-city energy & amenities tucked away in the foothills of the Rockies

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IT'S BOULDER
Run through Boulder—Endurance Capital USA™—where Olympians train, mountains frame every mile, and fall turns the city into a postcard.
THE VIEWS
Big city energy, small-town charm. Picture mountain backdrops, city buzz, fall foliage in Colorado and an electric finish line at the foothills of the Rockies you ll never forget.
This isn’t a course. It’s a highlight reel.
LULULEMON FOR ALL
Every finisher gets an exclusive, limited-edition lululemon Metal Vent Long Sleeve or Swiftly 2.0 Hip Length Long Sleeve. ($88 value) Not swag. A statement piece.
SUSTAINABLE
Boulderthon firsts in sustainability and innovation firsts: First race with 100% hemp bibs in 5K 100% recycled medals Designed to be lighter on the planet and bigger on impact
GOOD FOR YOU. BETTER FOR THE PLANET.
TECH-POWERED.
COMMUNITY DESIGNED.
DESIGNED BY RUNNERS. POWERED BY TECH. Personalized race insights. Smart tracking. Custom recaps. A community-designed medal you’ll actually keep. Your race. Your data. Your story.
THE VIBES
THE PARTY STARTS AT THE FINISH.
Epic after-party. Outdoor expo on Pearl Street in the heart of the city. Live music, brands, community, energy. “Boulderthon has the best expo I've ever been to!” - Dakota

Set beneath BOULDER'S iconic FLATIRONS

Boulderthon is one of the nation’s premier race weekends, welcoming more than 17,000 runners from all 50 states and 18 countries. The event has earned national recognition from Runner’s World, USA TODAY, ACTIVE, and HalfMarathons.Net. Held in Boulder—America’s Endurance Capital™—the race unfolds where Olympians train, mountains frame every mile, and fall turns the city into a postcard.

CHOOSE YOUR

DISTANCE

Boulderthon is a top-rated marathon event in the United States, held annually in Boulder, Colorado. Recognized by Runner;s World, USA TODAY, and Active as one of the best and most beautiful races, it attracts runners from all 50 states and around the world.

MARATHON

HALF MARATHON

10K RUN

5K RUN

KIDS RUN

BOULDERTHON MUST HAVES

RACE DAY INCLUSIONS

FUEL

Precision Fuel & Hydration stations every two miles.

ENERGY

Live music and community-powered cheer zones throughout the course.

CONNECTION

Real-time runner tracking with mid-race audio cheers.

CELEBRATE

You crushed it. Now relive it with an AI-powered Race Rewind—the first-ever Spotify Wrapped–style recap for your race. Celebrate six months of training, revisit every highlight, and share your achievement with the world. Powered by Laurel.

A PLACE LIKE NOWHERE ELSE

Don’t just take our
word for it

Rated 5 out of 5
"Community events like Boulderthon offer a unique opportunity to enrich the lives of locals, and to invite more people from around the country and the world to see why we love our home here at the foot of the Flatirons," said Boulder Mayor Aaron Brocket. "Local businesses see a boost, visitors leave feeling excited about their experience, and that creates benefits for our city that last a lifetime."
Mayor Aaron Brockett
City of Boulder
Rated 5 out of 5
"Boulderthon is a strategic asset for the City of Boulder and one of our most important annual events. In only its fifth year, Boulderthon now drives nearly $23 million in economic impact - supporting thousands of jobs and generating meaningful revenue for our hotels, restaurants, retailers, and small businesses. We are proud to welcome runners, fans, and community members from Boulder and around the world, and to recognize the vibrancy, economic vitality, and community benefit this annual event delivers to our city."​
John Tayer
CEO of Boulder Chamber of Commerce
Rated 5 out of 5
"Boulderthon consistently brings great energy and foot traffic to Avanti and race weekend is always a strong one for our business. Beyond the sales impact, it's an incredible community event that brings together locals, visitors and runners of all backgrounds in a way that feels uniquely Boulder."
Hayley Edmisten
Director of Marketing,
Avanti Food & Beverage

rated top 10 in America by USA Today

RUN GREEN. RACE STRONG.

SUSTAINABLE RACE BIB

Our race bibs are made from industrial hemp, one of the world’s most sustainable, recyclable, and 100% biodegradable materials.

110,000 cups saved from landfills

We anticipate keeping 110,000 cups out of landfills this year! We’ll have both Hiccup reusable cups and compostable cups along the course.

Infinitely recyclable hydration

Did you know that aluminum is infinitely recyclable? We’ll have water in aluminum cans at the finish line.

Run Boulder.
Run Boulderthon.

Join TENS OF thousands of runners from AROUND the world for a race experience that combines performance, beauty, and community in the Endurance Capital of America™.

Days
Hours
Minutes
Seconds
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An award-winning race staged in the Happiest City in America
National Geographic