Arvada, Colorado (United States of America) - "Ralston Creek Half Marathon & 5k". The Ralston Creek Half Marathon and 5K follow a mix of roads and bike paths on the west side of Arvada. The 5K is mostly flat and fast, with a small rise in the final mile. The opening four miles of the half-marathon are fairly flat, with a barely noticeable gradual gain in elevation. Miles 4 - 6.5 are rolling, with one good climb leading to the high point of the course atop Ralston Mesa. From there, the course is almost all down hill and flat to the finish. Aid stations every two miles. Finisher’s medals for all half Marathon finishers. The Ralston Creek Half Marathon & 5K is also the final event in the Racing Underground Winter Running Series with age group awards in every age category. Pick one race, or do all three! Series participants can choose the 5k-5k-5k Series or the 5k-10k-Half Marathon Series. https://www.racingunderground.com/winter-run-series