In 2012, the ERS was founded with the intent on creating an event production brand in the trail running category.  Since we started this journey the ERS has not only created that trail running brand, but we have built two great communities of support in Colorado and Southern California (San Diego).


Today the ERS is widely considered to be Colorado's Largest Trail Running Series and San Diego's fastest growing trail running series.  With a total of 12 events combined in the 2 regions, the ERS hosts more than 6000 beginner, intermediate, and experienced trail runners each year. 

Whether you are looking for a stroll along the water, some scenic single track, or a challenging hill/ mountain course, the ERS prides itself on offering the best trail race experience and atmosphere in the industry.

Every event within the ERS offers multiple race distance options, great course support, kid's races, and finish line festivals that the entire family can enjoy with music, food, games, raffle, and plenty of beer (for those over 21 years, of course)

The "Need to Knows"....

  • All race courses are subject to change at any time leading up to the race date due to circumstances beyond our control. This includes race dates, race times, and trails used.
  • Although we would like to get race courses to their exact and respectful distances, sometimes this may not be possible, and courses may measure longer or shorter than indicated. GPS between products will also always vary.

  • Aid Stations will include first aid, water, electrolyte, and nutrition

  • It is the responsibility of the runner to know the course. We mark the courses to the best of our ability with directional signs, mile markers, flour, and volunteers. We are not responsible for course sabotage and non-race personnel misdirecting runners, nor is the ERS responsible for any runner deciding to follow other runners in the wrong direction. If and when race courses are changed,  we will post updated course maps online and onsite race morning.

       For additional information and answers to FAQ's regarding this same subject matter please click, HERE

All races meet ATRA event standards

Presented By:


The ERS is proud to offer our very popular kid's dash at each of our 12 trail events. 

Registration Fee: $10

(Reg available race morning only)

Distance: 1/4-1/2 Mile

(Distance varies event to event based on age of kids)

Includes Kids Medal

100% of Kids Dash Proceeds benefit

Girls on the Run


Finish line Festivals

Join us for the after party!


The ERS offers some of the best post race food and activities you can find in the trail running community.


Proudly sponsored by some great local Colorado and San Diego companies , we offer Pancake Breakfast, Premium Sausages, Vegetarian, Coffee, and Beer, to name a few options.


Games, Drawings, and Much More...


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...and even if you don't love us, sign up anyways its free!

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© 2019-2020 Endurance Race Series, LLC