From US 101 in Marin County, exit San Anselmo (Sir Francis Drake). Drive about 20 miles west on Sir Francis Drake. Turn right onto CA 1, then after about 0.1 mile, make the first left onto Bear Valley Road. Drive about 2 miles to the junction with Sir Francis Drake, and turn left. Drive about 5 miles to the junction with Pierce Point Road, and turn right. Continue about 3 miles more to the trailhead on the left side of the road.
GPS coordinates: Latitude 38° 7’24.59″N, Longitude 122° 56’8.49″W