Boulderthon was named among the Best Fall Marathons by Runners World, as well as the best Half Marathon in Colorado and one of the Top 13 Most Beautiful Half Marathons in the World by HalfMarathons.net.
Boulderthon has doubled every year since its inception. In its third annual edition, Boulderthon drew runners from all 50 states as well as 18 countries, as the signature marathon showcased the world-class city of Boulder set at the foothills of the spectacular Flatirons.
Join us for the largest September running weekend in the U.S. on Sunday, September 29th, 2024 for the fourth annual Boulderthon Marathon in stunning Boulder, Colorado.
The course features an all-new, exciting Start downtown with a stunning course through Boulder, Colorado at the foothills of the Flatirons, before winding you to Downtown Boulder for an epic, one-of-a-kind finish on the historic Pearl Street Mall! Boulderthon is the perfect fall race to enjoy Boulder, Colorado, named the happiest & fittest city in America.
Boulderthon has instituted a new runner cap this year, has sold out every year, and is expected to sell out again.
Date: Sunday, September 29th, 2024
Start Time: 7am
Course Close: 2:30pm
Registration for the Boulderthon Half Marathon is now open.
Boulderthon also offers a Kids Run, 5K, 10K & Full Mararthon.
"Great Day, Great Race. I can’t imagine a marathon that is run any better. Everything went well, volunteers were plentiful and helpful, aid stations were great, and the weather was perfect for a long run. And Boulder turned out in force to cheer us on."
"Fantastic First. Terrific race, beautiful course. Staff and volunteers were first class all the way!"
"This was my 1st half marathon race and I had a blast! Everyone was in a great mood and the course was beautiful! Thank you all!"
95% of runners would recommend to their friends, with #1 reason being Downtown Finish & Course Views.