Head to Lake Carl Blackwell in Stillwater, OK for a unique endurance experience where you'll run a beautiful 3.1-mile trail loop as many times as you'd like, with fresh waves starting every hour—you're in complete control of when to keep going or call it a day, with zero judgment or DNF marks on your record. Your loops get timed and ranked by total combined time, so whether you're aiming for a 5K or pushing toward marathon distance, you'll have meaningful competition at your own pace while challenging your pacing strategy and endurance limits. This flexible format welcomes runners of all abilities and styles, and you'll get official results, rankings, and comprehensive data to review afterward.