Mammoth Bar is part of the California OHV system, therefore there is a $5 per vehicle use fee. You can also pick up an annual pass at the local ranger station that is good for use at all CA OHV parks. In addition to the trails in the hillsides there is a motocross track and a mini-bike track right on the river.
Auburn CA. - Turn right off hwy 80 onto Auburn/Foresthill Road, go approximately 2 miles, turn right on Old Foresthill Road and follow to entrance. 1,200 acres (hills), No. Fees. Open year round, Hours: Winter; 8am-5pm, Summer; 8am-8pm. Temperature: Winter; 30°-68°, Summer; 80°-100° Auburn State Recreation Area, P.O. Box 3266, Auburn CA 95604, (530) 885-5821 or (916) 885-4527. MC, ATV.