Near Baraboo in Sauk County, the 9,100 acre Devils Lake State Park surrounds Devils Lake which was formed by glacial moraine blocking two sections of the od Wisconsin River bed at a quartzite gorge. The lake is clear blue bounded by rocky bluffs. Starting on the north shore, the red-blazed Ice Age Loop is open to mountain biking and is a steep climb through pine forests and shag-bark hickory. This 6 mile loop on hardpack tracks is blazed in green and white. Bicycles are allowed only on the Ice Age Loop and the connector trail between the Steinkie Basin Loop and the North Shore Picnic Area.
The trailhead is off County DL about 1.5 miles east of the north shore park entrance, near the ampitheatre.
To reach mountain biking at the park from the south: From Interstate 90-94 just take exit 106 to Highway 33. Take a right at the stop sign and go to Baraboo. (13 miles) When you get to Baraboo Take a left at the 2nd stop light. (This is Business Hwy 12) Then go through town and watch for a sign to the park. You will turn left on Highway 123 and follow it straight out to the park.
Overall, Ice Age Loop is the 1st most popular mountain bike trail of all 20 mountain biking in Wisconsin.