Inaugural Boulderthon is confirmed for October 10th, 2021. Register now.


What is the date of the event?

The Inaugural Boulderthon®, the only Downtown Boulder Marathon & Half Marathon, will take place Sunday, October 10, 2021.

  • Our Race Expo will be October 9, 2021.

How do I register?

Registration is available online, at the Expo, and on Race Day. Last-minute registrations at the Expo and Race Day will incur an additional fee. Our best rates are available online.

What is the cost of the race?

Registration fees vary based on:

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

Please visit Register page to see current registration fees.

What does my registration fee go towards?

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, race bibs, barricades, hydration, equipment and timing services.

Can I get a refund if I cannot participate?

We understand things happen. Boulderthon® has a flexible cancellation policy.

Refunds & Deferrals
Runners who registered prior to October 11th, 2020 are not applicable for a refund unless the following circumstances apply, and are sent to military transfer, student transfer, visa rejection, pregnancy, or employment transfer. A 75% refund will be applied.

Refund policy for runners who registered after October 11th, 2020:
2 months prior to Race Date (next Race Date: April 25th, 2021)
No refunds for April 25th, 2021 edition of the race after: February 25th, 2021

Runners who registered after October 11th, 2020 may request a full-refund of their paid fee up to 2 months days prior to their registered event date. No refunds will be granted in the final 2 months preceding their event date. Please contact us about refunds at

Registration Transfers - 14 Days
No requests can be honored after: Sunday September 26, 2021
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 A registration transfer processing fee of $25 will be incurred.

Deferrals - 7 Days
No requests can be honored after: Sunday October 3, 2021
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 to request a deferral.

Can I transfer my registration to another person if I cannot participate?

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

Can I defer my entry to a future date?

Yes, as long as it is at least 7 days prior to Race Day. See above.

Can I participate if I do not have my race bib on race morning or decide to join the race without officially completing the registration process?

No, for the safety & security of all our runners and spectators, this is not allowed.

What is packet pickup?

All registered participants receive a race bag (packet or goody bag) that includes their official race number, race information, and promotional product samples. Your race bag must be picked-up on Saturday, October 9, 2021 from 9am-6pm at our Race Expo in Boulder.

What do I need to bring to packet pickup?

As a registered participant you will receive a final race confirmation sent via email a few days prior to race day. Please bring a copy of this confirmation and a photo ID to the Race Expo to receive your race bag.

Can I pick up another participant’s race bag?

Although we stress that it is very important that every registered participant pick up their own bag, we do realize that in some cases it is not feasible. If a participant is not able to attend the Race Expo and pick up their own bag, they can designate a proxy to do so by presenting a copy of the runner’s photo ID or a copy of the runner’s confirmation email. Please understand that without one of these documents we will not be able to release the race packet to anyone other than the registered runner.

Race Shirt sizes are not guaranteed; please arrive early for best selection.

What if I didn’t get my email confirmation or want to confirm my race entry?

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

Can I transfer to another distance before Race Day?

Yes. Please email 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.

Do you have any course time limit rules?

The Boulderthon® is open to all participants of age who are able to finish the marathon in 6 hours, and the half marathon in 3 hours. Participants wishing to complete their event within that timeframe will need to maintain a 13:43 minute/mile or faster pace. There will be no early start for runners.

If you plan on participating at a 13:44 minute pace per mile or slower, please be aware that our permit dictates that the streets that comprise the marathon route are reopened to vehicular traffic at 1:30pm. On-course support (aid stations) will close at this time.

Participants still out on the race course after 2:30pm will be asked to move to the sidewalks or re-route. SAG wagons will patrol the route providing support to these participants.

We also suggest that walkers and slower participants consider carrying a hydration pack that accommodates water and snacks.

Will you have Pace Groups?

We will offer free pace groups for the marathon and half marathon.

The pacers will be at the Starting Line 20 minutes before the start of the race. They will wear prominent singlets and they'll be carrying signs that show the pace that their group plans to run. The times offered for each race will range from 1:30:00 to 2:30:00 in the Half Marathon and 3:00:00 to 5:00:00 for the Full Marathon.

How do you capture my finish time?

Your official race bib has a timing strip on the back, so do not remove this strip. Once you cross the start line your timing strip activates, and will not stop until you cross the finish line. In addition, we will have various timing mats on the course to capture your progress along the way. Athletes vying for prize money will be judged on gun time, while age group awards will be issued based upon tag (chip) time.

Do you allow participants to walk in the races?

Of course! We do ask that you adhere to the time limit rules.

Do you allow participants to use headphones, phones, iPods, etc.?

We do not have any restrictions on the use of headphones, phones, or iPods. We strongly discourage the use for safety reasons. If you make a decision to wear a music-playing device during the race, please keep it at a low level so you can hear special instructions from course officials or emergency vehicles.

I love to run with my dog, may I bring him or her to run with me?

We also love our pups, but for safety reasons pets are not allowed on the course at any time. In addition the City of Boulder prohibits pets from being on the Pearl Street Mall.

Can I bike, rollerblade, roller skate, skateboard, etc. on the course?

No, we do not allow any “wheels” on the race course for safety reasons, other than approved wheelchair participants, emergency personnel or race officials . The use of “wheels” will result in a disqualification.

I’m a disabled athlete. Can I participate?

Yes, we will make every effort to provide a safe race experience for athletes of all abilities. If you are a disabled athlete and would like to compete, please email to ensure we can accommodate any special requirements.

Can I run or walk with a baby jogger or stroller?

No, we do not allow baby joggers or strollers on course.

Do you offer Gear Check?

Gear Check is available Sunday October 10, 2021, only. Please do not bring gear to our Packet Pickup on Saturday. Due to security reasons we cannot accept gear bags prior to Race Day morning. You may bring your bag to the Start line and our event staff will transport it to the Finish/Expo area for your arrival. Participants may only re-use the “Clear” plastic bag they received at the Expo. Simply tear off the Gear Check tag from your race bib and affix it with the small tie provided to you at the Expo. Your official race bib number is also your gear check number. We discourage you from placing valuables in the gear check bags. For security reasons we will not accept backpacks, luggage or any large bags. All personal items must be placed in a clear bag, where contents are visible. No exceptions.

Please do not leave your bag unattended outside the official bag drop area. Bags left unattended may be confiscated due to Homeland Security requirements.

Please claim your gear as soon as possible after you complete the race. At 3:00pm any unclaimed gear will be transferred to the Stronger Faster Boulder office located inside Whole Sol (1420 Pearl Street, Boulder).

Items not claimed in one week will be donated to charity.

Will I receive a goodie bag?

Of course! What race is complete without one? Runners will receive a Boulderthon® reusable goodie bag pre-packed with refueling food and water after they cross the finish line.

Where can my family and friends watch the race?

Please see our Spectator Guide & Cheer Stations for the best places to watch the race.

Can I register at the Expo or on Race Day morning?

Yes, you may register at Expo or Race Day morning for an additional fee.

Can I drive to the Start?

No vehicles will be allowed to access the Start area at the Boulder Reservoir. All participants will be shuttled from Downtown Boulder. Friends and Family may ride our complimentary shuttle to the Start. Priority boarding will be for runners first. Shuttles will be available to transport Friends and Family from the start back to between 8:45am-9:30am.

Will there be Mile Markers?

Thanks to our generous sponsors, each mile is clearly marked with “Feather Flags” along the course.

Is there tracking? How will I get my results?

Unofficial race-day results will be posted on as soon as available. Official results are posted to this site as soon as possible following the race. At any point in the race, friends and family can enter the participant’s name or bib number on the homepage and see progress and results (only available on Sunday). Participants can easily search for live results on race day from our home page.

Will there be photos?

Yes, photos will be available for review on shortly after the race.

Will you have water, aid stations, and restrooms?

The marathon course has 10 water stations, staggered approximately approximately every 3 miles. Energy gels will be available at Mile 20. Toilets will be available at the start, finish, and locations throughout the course.

A number of highly trained physicians, nurses, physical therapists and other medical personnel will be on hand throughout race weekend. There will be several medical stations positioned throughout the course, with a comprehensive set-up in the runner services area at the finish line. There will be a number of mobile units moving throughout the course. These units will be staffed by paramedics, EMTs and marathon staff. There will also be ambulances stationed at the finish line and throughout the course.

Do I need to be 21 to attend the Post-Race Party?

Absolutely not! Those 21 years and older are invited to enjoy a beer; you must have an ID and your bib, no exceptions. Beer is also available for purchase. All are welcome to enjoy the Post-Race Party.

What is your waste & recycling policy?

Boulderthon® is proud to be a Zero Waste event. Please do your part to help us exceed our goals. We will have Zero Waste stations set up at our Expo, Finish, Start, and locations on course. Thank you for keeping Boulder green!

What are the age limits for each race?

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.

Where should I stay?

We are working on securing discounted rates at our local hotel partners. We will update this section once available. Please visit check the Run page for our hotel partners.

What if my question didn’t make it into your FAQ?

Please email us at We are happy to help :)