Saltwater State Park
The saltwater shoreline park 20 miles south at Des Moines: camping to 40 feet at $37 on a 9-month window, with a $10 sanitary dump, rinse, and potable water on site. For a boat-and-camp trip it is the closest state-park pairing of shoreline and utilities to the city — under the Sea-Tac approach path, as the guide honestly notes.
