Southeast of Grayling in Au Sable State Forest, the Ambrose Lake Trail is a 9 mile loop open to ATV riding.
To reach the trailhead from the intersection of Main and SR 33 in Rose City, head west on Main (which turns into W. Rose City Rd.) for 5.5 miles. Go south on CR F7 (N. Fairview Rd.) for 1 mile. Go west on CR 20 for 1 mile. Head south on Piper Lake Rd. and almost immediately look for parking on the left.
Overall, Ambrose Lake Trail is the 26th most popular ATV riding trail of all 54 ATV trails in Michigan.