Mystery Bay State Park

Mystery Bay State Park on Marrowstone Island is a 10-acre marine park is reachable by car off of Highway 116 or boat. The park features 685 feet of saltwater shoreline on Mystery Bay and offers a spectacular view of the Olympic Mountains.

The park offers a single-lane launch ramp, which drops of the floats. A daily permit is available for watercraft launching, vehicle parking and trailer dumping at the park. Annual permits also may be purchased at State Parks Headquarters in Olympia, at region offices, online, and at parks when staff is available. The park also provides 683 feet of moorage and a boater pump-out station. Moorage fees are charged year-round for mooring at docks, floats and buoys from 1 p.m. to 8 a.m. Moorage permits are available at parks offering moorage. For information, call (360) 902-8844. 

The name "Mystery Bay" derives from smuggling activity on the island during Prohibition days when transporting booze from Canada was a profitable and somewhat honored occupation in northwest Washington. The harbor between Marrowstone and Indian Islands was one refuge used by smugglers to evade Coast Guard vessels who consider the disappearance of smugglers in the area "mysterious" and so the bay's name was born.

Summer: 6:30 a.m. to 10 p.m. Winter: 8 a.m. to 5 p.m. The park is open year-round for day use only.

State Parks Information Phone: 360-902-8844 Web Site:


Marrowstone Island, WA
United States
48° 3' 20.3328" N, 122° 41' 17.5848" W
See map: Google Maps
Marrowstone Island, WA