It’s hard for city kids to get lost these days, to find a hidden place where they can become who they are meant to be, test their courage on their own. But it’s not impossible.

One day a few years back, I took my 5-year-old son for a walk by the river. Alongside the narrow, dense span of woods south of the WMS Boathouse at Clark Park in Roscoe Village, we discovered a dirt bike track hidden behind a stand of tall trees. It was like we had stepped into some kind of 1980s childhood fantasy: The track—maintained by the Chicago Area Mountain Bikers, I later learned—had fearsome jumps and hairpin turns. Several teenagers were hurtling themselves over the course, doing impressive aerials. My son gazed at them in wonder. Walking farther, we found a second, smaller course, which had shorter jumps and a less steep ramp. My son looked up at me and said, “I want to do it.”

He’d barely taken off his training wheels, much less gone off-road, but the next day we went back to Clark Park. Part of me was proud, part of me was pretty sure he was going to break his neck as I helped him up the ramp and watched as he came speeding down and made it through the first turn, then up and over a small jump, before wiping out. When he got up, he was covered in dirt, and he was grinning.