The Porcupine Mountains Wilderness State Park offers more than 20 miles of designated mountain bike trails, with loops ranging from 1.5 to 10.5 miles. The trails serve as cross-country ski trails in the winter. (Note: trails may not be regularly maintained in the summer.) You can enjoy road biking from Ontonagon to the Porcupine Mountains on M-64/Memorial Highway 107 thanks to the wide shoulders. The Ottawa National Forest is also open to mountain biking, except in designated wilderness areas and on hiker-only trails. Adventure Mine has four miles of trails open for biking and hiking that weave around old mining foundations and historic mining pits. A mountain bike race called the Miner’s Revenge takes place each summer on these trails. Copper Peak has 5.5 miles of trails at the site of a historic ski jump. The challenging trails accommodate a wide range of skill levels and they include some exciting descents.