The Next Loop 50-Mile Challenge - Lake Carl Blackwell
Stillwater, United States • 21 Nov 2026
The Next Loop 40/50 Mile Challenge - Lake Carl Blackwell
The event uses a 3.1 mile (5K) loop at Lake Carl Blackwell in Stillwater, OK. The loop passes lakeside terrain, open grasslands, and wooded sections on a mix of dirt paths, grass, and lightly packed earth. The course features gentle rolling elevation and wide sections that provide consistent footing over repeated laps.
Runners complete repeated loops from a central start and finish area. A fully stocked aid station is available at every lap. Personal supplies may be accessed from a designated staging area each loop, and crew access is permitted in designated areas. Pacers are allowed according to event rules, and medical and race staff are on site throughout the event.
The format is a continuous loop trail race with a strict 12 hour time limit. Competitors are scored separately from participants in the concurrent Next Loop hourly format; both events run on the same 3.1 mile loop but use different race rules and scoring.
Target participants described for the event include runners attempting an initial ultra distance, athletes moving up from marathon or 50K distances, and experienced ultrarunners seeking a simplified loop format with centralized support.
Distances offered: Visit the organization's website for the most recent information.
- 40 Mile
- 50 Mile