Upland Loop - DT - Devil's Lake State Park - WI State Park pass required - Bike rentals available at Wildside Devil's Head Resort - ST, DT, DH - 10 minutes from Devil's Lake - $7/day - Bike rentals available onsite
Cam-Rock County Park - ST - 90 minutes from Devil's Lake
Blue Mounds State Park - DT, ST - xx minutes from Devil's Lake
The rocky, technical singletrack at Blue Mounds will appeal to skilled riders most, but there's enough intermediate trail here to make it worth the average riders time.
Kettle Moraine - DT, ST - xx minutes from Devil's Lake - Rentals available at Backyard Bikes in La Grange
For folks coming up from the Milwaukee or Chicagoland, your best bet is to stop for the singletrack in Kettle Moraine before or after visiting Devil's Lake. The extensive trail systems here offer options for all skill levels, with the moderate John Muir system and more difficult Emma Carlin loops. Expect lots of well-maintained, flowy, roller-coaster trail with the occasional root fest.