Registration is available online and at the Expo. Last-minute registrations at the Expo will incur an additional fee. There is no race day registration. Our best rates are available online. 

Registration fees vary based on:

• Race entry date
• Race package
• Additional merchandise purchased during registration

Please visit the "Register Now" page to see current registration fees.

Funds from runner registration fees are applied towards costs associated with event shirts, finisher medals, and a variety of operational costs such as: official permits, medical support, security, police, infrastructure, race bibs, barricades, hydration, nutrition, equipment and timing services.

We understand things happen. Entries booked prior to 12/31/2023 have a flexible cancellation policy. After 12/31/2023, registrations are non-refundable.

Refunds & Deferrals for prior to 12/31/2023

• Runners are entitled to a no-questions-asked full refund up to 60 days before the Race Date.
• No refunds will be granted in the final 2 months preceding the Race Date, except if the following circumstances apply: military transfer, student transfer, visa rejection, pregnancy, or employment transfer. In these cases, a 75% refund will be applied. Please contact us about refunds at support@boulderthon.org.

Registration Transfers - 14 Days Prior to the Race Date

• A request must be sent no later than two weeks prior to the event by the runner who purchased the registration with the name, address, email, gender and date of birth of the runner taking their place to support@boulderthon.org. A registration transfer processing fee of $25 will be incurred.

Deferrals - 7 Days Prior to the Race Date

• All deferrals are complimentary. Those who request to defer to the following event year will be provided with a registration link and instructed to register within one week of receiving the deferral link. Upon receiving a confirmation email after registering the deferral, they will be registered for the coming year’s event and it will require no further action. Contact us at support@boulderthon.org to request a deferral.
• Charity Bibs are NOT eligible for deferral.

Yes, as long as it is at least 14 days prior to Race Day. See above.

Yes, deferrals are complimentary up to 90 days prior to the race. Within 90 days of Race Day and up to and including Race Day, we are happy to process a deferral for any reason if you cannot run, for the following edition, for you for a $30 processing fee.  

If you did not get your confirmation email and would like to confirm that you are registered for the race, please email support@boulderthon.org.

Yes. Please email support@boulderthon.org 14 days prior to Race Day, and we can complete the transfer for you If it is less than 14 days before Race Day, then all event changes must be done in person at the Expo Change Booth. Please keep in mind if you are transferring from the half marathon to the full marathon you will be responsible for paying the additional cost. If you are transferring from the marathon to the half marathon we cannot offer any refunds or credits.

Yes, you may register at the Expo, but not on Race Day morning.

The age limits are ages 9 and older for the Half Marathon and ages 13 and older for the Full Marathon. For your safety, anyone participating in the event must be a registered runner.

We are so excited to offer charity bibs! Register as a charity runner for $69 for the Full or Half. 

As of 8/1 all choose you own charity spots are now full, but we have a limited number of spots remaining to fundraise for our Official Charity Partners, American Cancer Society and First Descents. Visit the Run For Charity Page to learn more.

Let's make a difference together!