Posey Island Marine State Park
October 2026
About
Posey Island Marine State Park is popular with kayak groups and porpoises, but, depending on the day, you may also have the place to yourself. Though Posey seems barren at first, a thorough perusal reveals meadow grasses, ancient Yew trees, bright orange lichen and wildflowers blooming in season. Photographers and painters have found endless creative opportunities here. The park is a 1-acre camping park with 1,000 feet of shoreline. Posey Island is part of the Cascadia Marine Trail. There is no potable water on the island, and visitors must pack out what they pack in.
Is Posey Island Marine State Park fully booked?
A campground showing no availability is almost never full for good. People cancel — plans change, weather turns, someone books three weekends and keeps one — and the site goes straight back into the booking system, usually without warning and often at odd hours. The reason sold-out campgrounds feel impossible is not that sites never free up; it is that nobody is watching at the moment they do.
CampHawk watches Posey Island Marine State Park in Posey Island, WA for you. We recheck it every 15 seconds, around the clock, and the moment a site opens we send a text, an email and a push notification, with a link straight to the booking page.
Searching is free and needs no account — the calendar above is live right now. Watching Posey Island Marine State Park for cancellations is the paid part.