Boulderthon, presented by lululemon, is a 501(c)(3) community nonprofit founded in 2021 by Phil Dumontet with a simple goal: to bring a world-class marathon to one of the greatest running hubs in the world. In only its fifth year, the 2025 edition of Boulderthon generated an estimated economic impact of $22.8 million in direct and indirect economic impact.

In just five years, Boulderthon has grown from 1,600 participants to more than 15,000 participants from around the globe – making it one of the fastest-growing races in the United States. It was recently recognized by USA Today as one of the Top 10 races in America.

Beyond race weekend, Boulderthon is deeply committed to giving back. The organization provides 250+ community bibs each year to ensure access for those who otherwise could not participate, leads ongoing volunteer and environmental adoption efforts with Tom Watson Park, hosts free women’s safety seminars, and invests in year-round community events that strengthen Boulder’s running culture.

It is a Boston Marathon Qualifying (BQ), USATF Sanctioned Event, measured by a Level A USATF Course Measurer, representing the highest level of certification for a marathon race. The race offers a full marathon, half marathon, 10K, 5K and children’s races. ?For more information, visit http://www.boulderthon.org.