The Next Loop Endurance Series - Lake Carl Blackwell - Stillwater
Stillwater, United States • 23 May 2026
The Next Loop Endurance Series at Lake Carl Blackwell
The Next Loop Endurance Series features a 50-mile and 40-mile challenge held at Lake Carl Blackwell in Stillwater, Oklahoma. The event is centered on a 3.1-mile (5K) loop trail, providing a continuous running format rather than an hourly setup. Participants in the 50-mile category complete 16 loops of the course to reach the total distance.
The course features a single, fully stocked aid station located at the start and finish area of each lap. This setup allows for simple logistics and frequent access to nutrition. Runners have a dedicated staging area separate from other participants, where they can store personal gear at their vehicles or in a designated space for use during each lap.
Available distances:
- 50 Mile Challenge
- 40 Mile Challenge
The event utilizes chip timing to record splits for every completed loop, allowing participants and crews to track pacing and performance trends throughout the day. There is a 12-hour hard cutoff for the challenge. While the race begins with a mass start, it includes specific age group divisions for Open runners, Masters (ages 50-69), and Grand Masters (ages 70+).
Pacers are permitted to join runners on the course after 4:00 PM. All pacers must check in at the designated station and wear official identification. Only one pacer is allowed to accompany a participant at a time, and they must enter and exit the course at the start and finish area. Visit the organization's website for the most recent information.