West of Oroville, the 28,450 acre Lake Oroville State Recreation Area has a 220 acre ATV riding facility called the Clay Pit Off Road Area.
To reach the trailhead from Highway 70, go east on Highway 162 (Oroville Dam Blvd.). Continue on Oroville Dam Blvd., turning right at Olive Hwy. (Highway 162), proceed approximately 6 miles on Olive Highway to Kelly Ridge Road. Turn left and Kelly Ridge Road ends in the Visitor Center parking lot.
Alternately from US70, take the Oroville Dam Road (Hwy 162) Exit West (left). Go aproximately 2mi to Larkin Road. Take a left on Larkin Rd and go aprox. 1 mi to the parking area.
There is no trail map available for this area -- it is an open riding area with no distinct trails to be mapped.
Overall, Clay Pit Off Road Area is the 20th most popular ATV riding trail of all 106 ATV trails in California.