Registration for Boulderthon 2023 is now open! After nearly tripling in size and selling out last year, Boulderthon has instituted a new 5,000 runner cap and is expected to sell out again this year. Register today.

THE SIGNATURE BOULDER MARATHON
WITH A DOWNTOWN FINISH

10.8.23

LEARN MORE
People gathered at the starting point of the Boulder marathon and texts like 'spectacular' and 'epic' written on the foreground
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People gathered at the starting point of the Boulder marathon and texts like
'spectacular' and 'epic' written on the foreground
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People gathered at the starting point of the Boulder marathon and texts like
'spectacular' and 'epic' written on the foreground
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People gathered at the starting point of the Boulder marathon and texts like
'spectacular' and 'epic' written on the foreground
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Finish line of the Boulderthon run with text overlay saying 'best Colorado
races'
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Aerial view of a park in Boulder with text overlay saying 'run a marathon in the
happiest city in America'
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aerial view of a road in the middle of the foothills with text overlay saying 'the
signature city marathon that Boulder deserves'
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arerial view of the city at the foothills with text overlay saying 'set at the
foothills of the rockies'
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aerial view of the city at the foot of the mountains with text overlay saying '3+
years in the making'
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aerial view of the Folsom Field stadium with a text overlay saying 'join the
Boulder community'
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aerial view of the city at the foothills with text overlay saying 'for the first time
in history, an epic downtown finish'
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aerial view of a road in the middle of the foothills with a text overlay that says
'feel on top of the world'

Boulderthon was named one of the Top 5 Best Half Marathons in the United States by Active.

Run a 5k, 10k, Half, or Full, at the foothills of the Rockies, in the stunning running mecca of Boulder. Run the streets Olympians train on, then celebrate at our epic after-party downtown!

Secure your spot now in Colorado’s largest fall running weekend! After nearly tripling in size last year and selling out, Boulderthon has instituted a new 5,000 runner cap this year and is expected to sell out again.