My home state is pretty flat. Except where it isn't. Like in Kettle Moraine State Forest, which, thanks to a 10,000-year-old glacial grudge match, is downright hilly. I grew up cycling in the state forest's Northern Unit, but the Southern Unit, with more than 30 miles of mostly singletrack, is the best place for knobby tires. My favorite ride: "Blue," a ten-mile singletrack loop with just enough switchbacks and rock gardens to keep things interesting. Like all of the trails here, it's hard-packed and fastand popular. But while these trails do see heavy use, they're also in great shape, thanks to meticulous upkeep. Backyard Bikes and Ski, in LaGrange, Wisconsin, 1.5 miles from the main trailhead, rents single-speeds, 29ers, and full-suspension rigs (from $30 per day; backyardbikes.com). Rent a cottage at Scenic Ridge Campground, on nearby Whitewater Lake (from $120; scenicridgecampground.com).