Registration for Boulderthon 2023 is now open! After nearly tripling in size and selling out last year, Boulderthon has instituted a new 5,000 runner cap and is expected to sell out again this year. Register today.
aerial view of Boulder, Colorado


What is the date of the event?

Boulderthon®, the Boulder Marathon & Half Marathon with a Downtown Finish, will take place Sunday, October 8, 2023.

  • Boulderthon offers Early Packet Pickup (open to all) beginning Saturday, 9/30/23 through Thursday, 10/5/23 at Boulder Running Company, 2775 Pearl St, Boulder, CO 80302, during their normal hours.
  • Our Official Expo & Packet Pickup will take place on Pearl St Mall between 14th & 15th, on Friday, 10/6/23, from 2pm-6pm, and Saturday, 10/7/23 from 10am-4pm.

How do I register?

Registration is available online and at the Expo. 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.

Are participants allowed to wear their own Hydration Packs?


Will there be bathrooms on the course?

Yes! In addition to portlets at the Start & Finish, portlets will be located at every Hydration & Aid Station on course.

Can I get a refund if I cannot participate?

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

Refunds & Deferrals

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

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 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 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.

Is Boulderthon a Boston Qualifying/Boston Qualifier (BQ) Marathon?

Yes! Boulderthon 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 series.

What is Packet Pickup?

Boulderthon offers Early Packet Pickup (open to all) beginning Saturday, 9/30/23 through Thursday, 10/5/23 at Boulder Running Company, 2775 Pearl St, Boulder, CO 80302, during their normal hours.

Our Official Expo & Packet Pickup will take place on Pearl St Mall between 14th & 15th, on Friday, 10/6/23, from 2pm-6pm, and Saturday, 10/7/23 from 10am-4pm.

What percentage of the run is on gravel vs. pavement?

Roughly 30% of the Half Marathon, or 4 miles, is on gravel. The remaining 70% is on paved roads or Multi-Use Path (paved). The Multi-Use Path sections of the course are noted on the Course Maps with green highlighting.

Roughly 50% of the Full Marathon, or 13 miles, is on gravel. The other 50% is on paved roads or Multi-Use Path (paved). The Multi-Use Path sections of the course are noted on the Course Maps with green highlighting.

Boulderthon’s 5k, 10k and Kids Run are 100% on paved roads or Multi-Use Path (paved), and 0% on gravel.

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?

Boulderthon® is open to all participants of age who are able to finish the marathon in 6 hours, and the half marathon in 6 hours. Participants wishing to complete their event within that timeframe will need to maintain a 13:43 minute/mile or faster pace for the marathon, and 27:29 minute/mile for the half. There will be no early start for runners.

If you plan on participating at a slower pace, please be aware that our permit dictates that the streets that comprise the marathon route are reopened to vehicular traffic at 2pm. On-course support (aid stations) will close at this time.

There are no time limits for Boulderthon’s 10k or Kids Race.

Will you have Pace Groups?

Yes! Beast Pacing will be pacing the 2022 Boulderthon. Beast Pacers will hold Pace Signs and will be located at the Start of the Half & Full Marathon. Only the Half & Full Marathon will have Pace Groups. Pace Groups are below:

Marathon: 3:30, 3:45, 4:00, 4:30, 5:00 and 5:30

Half Marathon: 1:30, 1:45, 2:00, 2:15, 2:30, 2:40

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 para-athlete. Can I participate?

At this time, Boulderthon is not be able to offer a para-athlete or wheelchair division due to its course configuration. As our event grows, we hope to be able to add this division in the future. If you have any questions or feedback, please email

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 on Sunday for the Half and Full Marathon 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.

What if I don’t finish?

There is a SAG vehicle that will follow the last runner. All runners who want a ride back to the Finish can wait for the vehicle.

Will I receive a goodie bag?

Of course! What race is complete without one? Runners will pick up their Goodie Bag at the Expo. At the Finish, runners will be offered water and bananas after they cross the finish line.

Will I receive a Finishers’ Medal?

Of course!

What does your Finisher Medal look like?

The 2021 edition of our medal is here. 2022 is not revealed until Race Day!

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?

You may register at Expo, but not on Race Day morning.

Can I drive to the Start?

All Half & Full Marathon runners will choose a transportation option (either Shuttle or Runner Drop Off Pass) at the time of registration.

Shuttle Transportation is for the Half & Full Marathon only. Shuttles depart from Boulder High School beginning at 5am and transport Half & Full Marathon runners to the Start Line at the Boulder Reservoir.

Due to space restraints at Boulder Reservoir, all runners being dropped off at the Reservoir will require a Runner Drop Off Pass. No drop offs are allowed without a Pass.

For the Kids Run, 5k, 10K: there are no Shuttle Passes or Runner Drop Off Passes. The Kids Run and 5k will start and finish in the same location on 17th & Pearl St.

Slots are limited and will be filled on a first-come, first-serve basis. Your preferred choice may not be available.

There is bike parking at the Boulder Reservoir. You are also welcome to walk/run. There will be no shuttles back to the Reservoir after the race.

Refer to the website section RACE WEEKEND for the latest Course Maps and Start and Finish information.

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?

Yes! Both the Marathon & Half Marathon course has Water Stations on course, staggered approximately every 3-4 miles. Scratch Labs Energy Chews (Sour Cherry - caffeinated, Orange - uncaffeinated) will be available at approximately Mile 9 on the Half Marathon and Mile 22. Toilets will be available at the start, finish, and at every Water and Aid station throughout the course. Please check our Course Maps, under Race Weekend, on our website for the locations of each Water & Aid Stations.

Will you have some type of Hydration Mix & Gels on the Course?

Yes! We will serve Ultima Replenisher Hydration Mix (variety of flavors) beginning at approximately Mile 6 on both the Half Marathon course and Full Marathon Course and approximately every 3-4 miles after that. Skratch Labs Energy Chews (Raspberry) will be available approximately Mile 9 For the Half Marathon, Mile 22.5 for the Full, and Mile 4 for the 10k. Please check our Course Maps for the locations.

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 Finish Festival on the Pearl St Mall between 14th & 15th?

Absolutely not! Those 21 years and older are invited to enjoy a drink at Avanti F+B, where our Official After Party is; you must have a valid ID. Drinks specials will be available for purchase. All are welcome to enjoy the Post-Race Finish Festival.

What is your waste & recycling policy?

Yes! Partnering with Eco-Cycle, 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?

Boulderthon has secured discounted rates at preferred partner hotels. Please check out our partnered hotels here.

How does the Charity Registration work? Can I fundraise money for any charity?

We are so excited to partner with the RACE Cancer Foundation as our Boulderthon Charity! To sign up for a charity entry, select the "Charity Runner" option at checkout. You'll be required to fundraise at least $300 before race day, which will go towards fighting cancer through action and prevention.

At this time, we are only able to offer charity registrations to fundraise for RACE Cancer Foundation. If you have another fundraiser you would like to raise money for, we would love for you to use the Boulderthon as your platform! Simply register for a regular entry and fundraise money through your platform of choice. Let's make a difference together!

What is the elevation of the course?

The elevation of the Start at the Boulder Reservoir is approximately 5,177′. The elevation of the Finish is approximately 5335’.

What are the Elevation Gains?

The elevation gain of the Boulderthon Half Marathon is approximately 525 feet. The elevation gain of the Boulderthon Marathon is approximately 1592 feet.

The elevation gain of the Boulderthon 5k is 332 feet. The elevation gain of the Boulderthon 10k is 538 feet. The elevation gain of the Boulderthon Kids Run is 144 feet.

Please see our Course Maps for more information.

Who won Boulderthon in 2022?

The winners of the 2022 edition of Boulderthon are below:

2022 Boulderthon Marathon Winner - Female
Marie Morrier - Denver, CO - 3:02:59 (Course Record)

2022 Boulderthon Marathon Winner - Male
Kurt Roeser - Longmont, CO - 2:31:51 (Course Record)

2022 Boulderthon Half Marathon Winner - Female
Neely Spence Gracey - Lafayette, CO - 1:16:09 (Course Record)

2022 Boulderthon Half Marathon Winner - Male
Alejandro Martinez Ambrosio - Boulder, CO - 1:08:20 (Course Record)

2022 Boulderthon 10k Winner - Female
Jessica Scheriff - Denver, CO - 35:18 (Course Record)

2022 Boulderthon 10k Winner - Male
Carson Hume - Fort Collins, CO - 31:39 (Course Record)

2022 Boulderthon 5k Winner - Female
Shelley McDonald - Loveland, CO - 18:37 (Course Record)

2022 Boulderthon 5k Winner - Male
Koy Cunningham - Colorado Springs, CO - 16:17 (Course Record)

Full results are available on our Results & Photos page.

What are the Course Records?

The Boulderthon Marathon & Half Marathon Course Records are below:

Marathon - Female
Anke Schoettle - Denver, CO - 3:25:52. Oct 10, 2021.

Marathon - Male
Mike Binder - Erie, CO - 2:53:11. Oct 10, 2021.

Half Marathon - Female
Kathryn Harrison - Denver, CO - 1:26:11. Oct 10, 2021.

Half Marathon - Male
Joel Toppin - Wesminster, CO - 1:14:143. Oct 10, 2021.

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

Please email us at We are happy to help :)