Ironbull Ultra Trail

Rib Mountain Trail Races, staged by IRONBULL in Wausau, Wisconsin, offer 50k, 25k, 15k trail runs and a kids run. The 2025 course returns to Rib Mountain State Park trails, with each distance around 10.6 miles per loop: the 15k is a single loop, the 25k is 1.5 loops, and the 50k is three loops. Runners encounter the park’s scenic, glacially eroded terrain, including twists, climbs, and hardwood forests.

Two main aid stations (top at 5 miles and bottom) plus water along the course support efforts. Finisher celebrations at the finish line feature food, music, and beer; cupless, composting, and Trail Sisters–approved event with sponsor support. Visit the organization's website for the most recent information.