A mountain bike version of the classic Morgul-Bismarck loop. The ride is a mix of smooth gravel road-type riding and some mild singletrack; this is an easy ride from a technical standpoint, but it can be a great aerobic workout if you want it to be.
Starting from the Coalton trailhead, head out on Meadowlark Trail (it's the trail that goes north, not the one that goes west). This eventually runs into Mayhoffer-Singletree Trail, where you'll take a left. Follow this trail until it crosses a road and runs into Cowdrey Draw. At the end of Cowdrey Draw, continue on Community Ditch (to extend the right, you can take a right on Community Ditch and ride the Marshall Mesa trails until they meet back up with Community Ditch near Highway 93). Take Community Ditch all the way to Highway 93, then, being very vigilant about traffic, ride a few yards south on the highway until you get to the end of Greenbelt Plateau. Ride Greenbelt Plateau until it meets up with the High Plains Trail near Highway 128. Turn left on High Plains, and take it all the way back to the Coalton trailhead (High Plains turns into Coalton at the top of the hill).