tBunk Endurance Challenge

Prepare to challenge yourself at the tBunk Endurance Challenge 50K, set to unfold on November 8, 2026, in the scenic Southern Kettle Moraine State Forest near Whitewater, Wisconsin. This event, renowned for its "tough but fair" nature, honors ultrarunning legend Tom Bunk, with all proceeds dedicated to the Tom Bunk Memorial Fund to support local trail projects.

The 50K course primarily utilizes the Nordic Blue loop, a demanding 9.19-mile circuit featuring significant elevation gain, often cited between 750 and 1,700 feet per loop. Runners will tackle repeated climbs and descents through runnable trails that, while not overly rocky, can conceal trip hazards under a blanket of fallen oak leaves. Your journey to 50K will include multiple loops of this challenging terrain, culminating with a 3.66-mile Green loop. Typical race day conditions in early November present highs around 50°F and lows near 32°F, with a 10% chance of precipitation, ensuring a true test of endurance against potentially varied elements.

Runners will find a fully stocked, manned aid station at the start/finish area, offering a wide array of food, fluids, and hot items, plus an unmanned aid station with essentials halfway through the Blue loop. The low-key atmosphere and supportive community make tBunk Endurance Challenge an ideal setting for both seasoned ultrarunners and those looking to conquer their first 50K. Drop bags are accessible at the start/finish to keep your personal supplies close.