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 15 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.