All-weather surface doubletrack with zero technical features on the main trails make this easy for the kids. From the large sign at the parking lot, take either main trail for a quick lap. The smaller entrance through a gate directly west of the parking lot has a lot of dog walkers. A sharp turn at the corner of the houses will turn this into a 1.5 mi loop.
The southwest corner links up with the bike path along US-36 (Denver-Boulder Turnpike), with the "Boulder Overlook at Davidson Mesa" close by.
If parking is a problem, you can park on the other side of McCaslin Blvd. at the Harper Lake Trailhead and take the underpass.