Sterling Ranch, Littleton, CO. 5K: 3-miles, 13 obstacles; Classic: 8-10 miles, 25 obstacles; Competitive Race: 8-10 miles, competitive race wave, first access to the course, exclusive challenges. New Venue, New Course. This is gonna be an absolutely insane weekend of expansive views and mud-drenched rolling hills criss-crossing Sterling Ranch just 20 minutes from downtown Denver. So gather up your muddin’ crew and get ready to push yourselves to the next level.