About This Race
The 100-mile distance doubles the challenge of the 50-mile option, requiring runners to complete additional loops that test mental fortitude as much as physical endurance. This distance demands experienced ultrarunners who can manage pacing, nutrition, and gear strategies across the extended time commitment while navigating familiar terrain that becomes increasingly demanding with each successive loop. The extended cutoff window allows for a methodical approach, but runners must prepare for the psychological challenge of covering ground they've already traversed multiple times as fatigue accumulates.
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.
Elevation Profile
Elevation profile estimated from terrain data. Actual course may differ.
The course gains 2,671 ft over 100 miles, with the steepest section between mile 97–mile 97.
Location
Aid Stations
2 stations along the course
Mid-loop Aid Station
water, electrolyte
Unmanned station at halfway point of each loop
Main Aid Station
water, electrolyte, food, hot_beverages, made_to_order_food
Extensive menu with 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.