ALL pre-registered runners will receive a gender specific T-shirt (tech tee) upon packet pickup. When registering for your event online you will have the opportunity to select the correct shirt size.

Important-Only those people that PRE-register for an event will be guaranteed to receive a T-Shirt with their registration, while ALL packet pickup and race day registrations will be asked to wait until after the designated event to pick up their race shirt. Please note, that race day registrants will not be guaranteed the correct size shirt if any at all. Thank you for understanding this policy, as we want to make sure those runners that register early do receive the shirt they requested.   

ALL FINISHERS, regardless of distance will receive a medal. Starting in 2017, the Endurance Race Series will offer a custom race medal to the Half Marathon and 10K finishers, while the 5K will receive a dedicated "5K course medal". 

If you register for a specific race distance and need to upgrade or downgrade, you may do so by contacting our staff before the registered event. 

  • $30 Upgrade Fee is required for 10k to Half
  • $15 Upgarde fee is required for 5k to 10k
  • No refunds will be given for downgrading

Season Pass holders that finish all 10 races will receive a special "SEASON PASS AWARD" and "SEASON PASS MEDAL" at the conclusion of the series.


Thank you for choosing to participate in the Endurance Race Series, Colorado's Largest Trail Race Series. We know there are many events out there to choose from, so your participation is much appreciated. 

Aside from our Single event registration or any of our "Pass Registration" , the ERS also offers our very popular: "PICK 6" registration option.

Sign up for any 6 of the the races within our series at one time and instantly receive 25% off your TOTAL registration fee!!