Thunderdown in the Underdown

Still rowdy since 1989, the Underdown Trail Races are grassroots trail runs and mountain bike races in Northern Wisconsin. It’s conveniently located only 6 miles off of Highway 51 and offers racers a wilderness experience on challenging trails formed from glaciers that swept the area thousands of years ago. The course is primarily singletrack climbing hills (up to 75!) that pass by isolated lakes with dozens of boardwalks.