About This Race
The tBunk Endurance Challenge presents itself as a tough but fair test of endurance running, designed to challenge runners without subjecting them to unnecessary suffering. Set in the rolling hills of Wisconsin, this event offers both 50-mile and 100-mile distances on a 9.19-mile loop course that delivers consistent elevation gain throughout. What sets this race apart is its commitment to maintainable trail conditions regardless of weather. While early November in Wisconsin can bring temperature extremes and challenging conditions, the course remains runnable, making it an attractive option for runners seeking to attempt a new distance or chase a personal record. The event emphasizes testing mettle over patience, suggesting a well-organized experience focused on the running itself. The race operates on a simple loop format with reliable aid station support, including both unmanned and fully-stocked manned stations. The main aid station promises an extensive menu of ultra-running nutrition plus hot beverages and cooked-to-order food, indicating a runner-focused approach to fueling during long efforts.
The race unfolds entirely on the Nordic Blue loop, a 9.19-mile circuit that delivers 1,700 feet of elevation gain per lap. This creates a rolling challenge that accumulates significant vertical gain over the full distance while maintaining a predictable rhythm for pacing and nutrition planning.
Runners will encounter an unmanned aid station at the halfway point of each loop, with the fully-stocked main aid station positioned at the start/finish area. The consistent loop format allows for strategic planning and crew support while the maintained trail surfaces ensure reliable footing regardless of weather conditions.
Aid Stations
2 stations along the course
Halfway Point
water, electrolyte
Unmanned aid station
Start/Finish
water, electrolyte, food, hot beverages, cooked food
Manned aid station with extensive ultra-running menu and hot food cooked to order
Practical Info
Early November in Wisconsin typically brings cool temperatures with potential for significant temperature swings and varied conditions including possible frost or snow.
Best For
Notable Features
The tBunk Endurance Challenge stands out for its philosophy of being tough but fair, emphasizing challenge over suffering. The consistent 9.19-mile loop format with 1,700 feet of elevation gain per lap creates a predictable yet demanding course structure. The race's commitment to maintaining runnable trail conditions regardless of weather, combined with comprehensive aid station support including hot food and cooked-to-order options, reflects a runner-centric approach that prioritizes the endurance challenge while supporting athlete success.