Underdown Trail Races

The Underdown Trail Races, organized by IRONBULL, are grassroots trail running and mountain biking events held in Northern Wisconsin. Scheduled for August 16, 2025, participants can choose from various distances, including a 60k, marathon, and half marathon for runners, as well as mountain bike races of 111 miles, 37 miles, and 16 miles. The course features challenging singletrack trails with numerous hills and boardwalks, providing a unique wilderness experience.

The event emphasizes a fun and intimate atmosphere, with amenities such as aid stations, awards, and an after-race party with live music. Proceeds support trail maintenance and development. Visit the organization's website for the most recent information.