Northwest of Grand Rapids and west of Mears in Oceana County, the 3000 acre Silver Lake State Park has a 450 acre ORV area with sand dunes.
To reach the dirt biking trailhead from Mears on US31, use the Hart or the Shelby exits and then follow the signs.
Note: avoid weekends and especially holidays. This ORV area is very popular and gets very crowded.
Overall, Silver Lake is the 6th most popular dirt bike trail of all 63 dirt biking rides in Michigan.