The Next Loop Endurance Series | Half Day Forest Preserve 2026

The race.

The Next Loop Endurance Series Half Day Forest Preserve takes place August 29, 2026, in Vernon Hills, Illinois. Runners complete a 3.1-mile trail loop, with new loops starting each hour on the hour. You decide after each loop whether to run another or stop; all completed loops are officially timed and counted toward your score, with no penalties for stopping and no DNF designations. The course is a scenic, clearly marked trail with a central base area for start and finish, plus an aid station available each hour. Completed loops can accumulate to standard distances: one loop equals 5K, two loops equal 10K, four loops equal a half marathon, and nine loops equal a marathon. Official timing and rankings are provided for each completed loop, with results ranked by total loops completed and combined time.