In the Nez Perce National Forest, the Kelly Mountain Trail (#121) is a great dirt biking route. The trail runs south from Coffee Can Saddle, past Kelly Mountain, and ends at CR1614 near Howard Ranch.
Directions to trailhead: Access from the south leaves US Highway 95 near the south city limits of Riggins. The route crosses the Little Salmon River and follows the Salmon River Road #1614 for 9.7 miles. At milepost 9.7 you will turn north and travel on the Grangeville-Salmon Road #221. You will encounter a single lane road climbing steeply out of the canyon for 15.2 miles where you turn onto Forest Road #394 and travel east for 1.7 miles to a right on an unnamed road. Go .7 miles to a left. Then go .2 miles to a right. The trail is on the right about .5 down the road.
Overall, Kelly Mountain Trail is the 19th most popular dirt bike trail of all 53 dirt biking rides in Idaho.