Anderson Marsh State Historic Park is a California State Historic Park and nature reserve preserving a tule marsh, archaeological sites of the Pomo people, and historic ranch structures. It is located in Lake County, California, USA.[2] Anderson Marsh is located at the head of Cache Creek on the southeast corner of Clear Lake, the largest natural lake completely within the borders of California.[2] The park is between the cities of Lower Lake and Clearlake on State Route 53, north of Calistoga in the wine country.[3] The park is open year-round.[4]