Boulderthon Marathon & Half Marathon

September 28, 2025

Boulder

Road

Distances

Marathon, Half-Marathon

Starting Time

7:30 AM

Fees

$169+

Perfect For

Beginner Friendly, Destination Race, Large Crowds, Big Finisher Party, Well Organized

Ready to sign up?

10,000+

Some Hills

Mountain Views

High: 61°

/ Low: 44°

Tucked away in the foothills and Valleys of the Rockies, Boulderthon is a destination race for a reason. With awe-inspiring backdrops of the mountains and beautiful trails throughout, the landscape alone makes it worth running. Not to mention, Boulder is often named the Happiest Place in the United States, so when you’ve completed the race and ran through Downtown Boulder, be sure to celebrate and enjoy the joy of the state!

Boulderthon was ranked among the top 10 races in the country by USA Today.

The start line for the half marathon is on 21st and Pearl, kicking runners off at 7:30 am sharp along Pearl Street. Along the Pearl Parkway, runners will intersect Cotton Lake and Valmont Road before turning left onto 61st Street. At mile 5 it’s onto 63rd Street before turning around at mile 6. Instead of backtracking, however, it’s a turn onto Jay Road, then onto 57th Street and Independance Road at mile 8. Through Hayden Lake, runners persist through the foothills until they reach Mapleton Avenue, the final destination before reaching the finish line. With a 7500 participant cap, Boulderthon is truly one for the books. Spectacular by every definition, all participants can expect a 5-star experience from beginning to end. For the highest achievers, this event offers both cash prizes, finisher’s awards, and 50% off next year’s registration!

Boulderthon Marathon & Half Marathon Results

Overview

Located in northwestern Colorado just 30 miles from downtown Denver, the Boulderthon Marathon and Half Marathon is part of Colorado’s largest Fall race series and is dubbed one of the top-rated marathons in the United States. Destination Race, Large Crowds. Voted the #1 Most Beautiful marathon and half marathon in Colorado, and among the most beautiful in the world, Boulderthon brings in over 10,000 participants annually from 50 states and 18 countries. Tucked away in the foothills and Valleys of the Rockies, Boulderthon is a destination race for a reason. With awe-inspiring backdrops of the mountains and beautiful trails throughout, the landscape alone makes it worth running. Not to mention, Boulder is often named the Happiest Place in the United States, so when you’ve completed the race and ran through Downtown Boulder, be sure to celebrate and enjoy the joy of the state! Boulderthon was ranked among the top 10 races in the country by USA Today.

Course Description

Past Results

Boulderthon Marathon & Half Marathon Results