Posey Island State Park is a publicly owned recreation area consisting of 1acre Posey Island in San Juan County, Washington. The island is located north of Pearl Island, near Roche Harbor, San Juan Island. It has about 1000ft of saltwater shoreline and is part of the Cascadia Marine Trail, with all campsites restricted to visitors arriving in non-motorized watercraft. The island-park is managed by the Washington State Parks and Recreation Commission.
