Southwest of Encampment in the Medicine Bow National Forest, there is an excellent ATV trail following the Continental Divide northwest from SR70. The trailhead parking is at Battle, about 12 miles southwest of Encampment on SR70.
The Snowy Range Mountains section of the Medicine Bow National Forest has miles and miles of forest roads open to ATV riding. Make sure you have the current Wyoming ORV permit.
Overall, Sierra Madres - CDT is the 13th most popular ATV riding trail of all 27 ATV trails in Wyoming.