Hope Island State Park is a marine park in Mason County, Washington, on Puget Sound, reachable only by boat east of Steamboat Island near Totten Inlet. Its 106 acres include old-growth forest, salt marsh, and 1.5 miles of beach, supporting quiet shoreline recreation such as beachcombing, birdwatching, fishing, clamming, hiking, picnicking, and camping. The island entered the state park system in 1990 after its acquisition from private owners and has since been administered as a satellite of Jarrell Cove State Park. The park remains intentionally undeveloped, with no water available on the island and bans on open fires and pets.