Tucked into a picturesque valley below the iconic Flatirons, Boulder, Colorado sets the backdrop for the top-ranked, signature Boulder Marathon, Boulderthon. Boulder is a world-class destination offering 300 days of sunshine and endless recreation, shopping, dining, cultural and entertainment choices. It's no wonder National Geographic named Boulder the Happiest City in America.
Join us on Sunday, Oct 8, 2023 for the 3rd annual Boulderthon in stunning Boulder, Colorado.
The course takes you through the beautiful back roads of 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.
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.
Boulderthon is also a Boston Marathon Qualifier.
Registration for the Boulderthon Marathon is open.
Boulderthon also offers a Kids Run, 5K, 10K & Half Marathon.