Colorado · Marathon · Half
Boulder Marathon
Boulder Marathon is a marathon and half marathon event held in Boulder, Colorado. It is usually held in September; the exact date hasn't been confirmed in the listing yet. About 15,000 runners take part across all distances.
- Usually held
- September
- Location
- Boulder, CO
- Field size
- ~15,000 runners
Race details
- Usually held in
- September (date not confirmed)
- Location
- Boulder, Colorado
- Distances
- Marathon, Half
- Field size
- About 15,000 runners
- Course
- Rolling hills
- Registration
- boulderthon.org
- Official website
- bouldermarathon.com
About the Boulder Marathon
Boulderthon, branded as The Boulder Marathon, is Colorado's largest fall running event, with a marathon, half, 10K and 5K through Boulder's foothills that finish on the historic Pearl Street Mall. It has grown explosively, drawing 15,000+ runners and selling out each year.
Rankings and notes
- Rankings and awards
- Colorado's largest fall race; has roughly doubled in size every year and sold out every edition; draws runners from all 50 states
- Notes
- Popular Colorado marathon
More marathons in Colorado
Coming up next, by confirmed date.
-
Colorado Springs Marathon, Half, 5K, and Kids KColorado Springs, COMarathonHalf Marathon10K5K +1 more
-
Windsor Marathon, Half Marathon, 10k, 5k & 1 Mile RunWindsor, COMarathonHalf Marathon10K5K +1 more ~660 runners
More races in Boulder
More upcoming races in Colorado
Keep exploring
- All races in Colorado
- 5Ks in Colorado143 upcoming races
- 10Ks in Colorado63 upcoming races
- Half Marathons in Colorado38 upcoming races
- Marathons in Colorado10 upcoming races
- Half Marathons in the United States1,289 upcoming races
- Marathons in the United States353 upcoming races
- September Marathons
- Marathons in Utah13 upcoming races
- Marathons in New Mexico5 upcoming races
- Marathons in Kansas4 upcoming races
- Marathons in Nebraska1 upcoming race
Guides from the RaceRove blog
- 7 min read How to Find a 5K, 10K, Half Marathon or Marathon Near You A practical way to find running races near you: pick a distance, decide how far you'll travel, read the listing properly and confirm the details before you register.
- 9 min read How to Run a Race in All 50 States How to plan a 50-state running challenge: set your own rules, group states into trips, build a calendar around the seasons, budget for it and keep track of every finish.
- 8 min read How to Choose the Best Half Marathon for a PR, Racecation or 50-State Challenge The best half marathon depends on what you want from it. How to choose a course for a personal record, a race worth travelling for, or an efficient stop on a 50-state challenge.
- Blog All guides Planning advice for finding, choosing and travelling to races.
Boulder Marathon: common questions
- When is the Boulder Marathon?
- The next date hasn't been announced in the listing yet. The race is usually held in September. Check the organiser's website for the official date.
- Where is the Boulder Marathon held?
- In Boulder, Colorado.
- What distances does the Boulder Marathon offer?
- Marathon and Half.
- How many people run the Boulder Marathon?
- About 15,000 runners across all of its distances. That figure is an estimate of the field size, not an entry cap.
- How do I register for the Boulder Marathon?
- Registration is handled by the organiser at boulderthon.org. Entry fees, caps and deadlines are set there.
Plan this race in RaceRove
Save it to your plan, compare it with other races, check typical race-day weather and track your 50-state progress in the interactive app.