From San Francisco and Santa Rosa areas:
Take Highway 101 north to River Road just north of Santa Rosa. Turn left on River Road and take it to Guerneville, here River Road becomes Highway 116. Continue Through Guerneville on Highway 116 to Scenic Highway One and turn right (north) through Jenner for about one hour to the city of Gualala. After crossing the bridge over the Gualala River take the first right(about 1/2 mile) on Old State Road and follow the park signs. This will be your fastest way from Santa Rosa.
From Sacramento and Vallejo area:
Take Highway 80 to Highway 37 in Vallejo to Highway 101 north through Santa Rosa to River Road. Follow the above directions from River Road.
From Eureka and Northern California:
Take Highway 101 south to either Highway 20 from Willits to Fort Bragg then south on Scenic Highway One or take Highway 128 from Cloverdale to Navarro River Beach then south on Highway One to the City of Gualala. After driving through Gualala, Turn left on Old State road and follow the Park Signs.
Motor Homes and Trailers, it is not advised to take Highway One out of Leggett or Mountain View Road out of Boonville or Skaggs Spring Road out of Geyserville or Highway One out of Sausalito.
DO NOT follow the Yahoo! Road map directions, they are WRONG!