Fee: No fees listed on park page
About this park
Posey Island is a one-acre marine park north of Pearl Island near Roche Harbor. The tiny island has two primitive group campsites and is a good overnight stop for kayakers. Campsites are part of the Cascadia Marine Trail and are reservable only by those arriving by human-powered vessel. Visitors in motor boats are limited to day use, and there is no garbage service on the island.
Posey Island State Park FAQ
Where is Posey Island State Park located?
Posey Island State Park is in Friday Harbor, Washington, at Pearl Island. GPS coordinates: 48.61834, -123.16798. Get directions.
Is there an entrance fee at Posey Island State Park?
No fees listed on park page. Fees can change by season, so confirm with the park before you go.
How do I contact Posey Island State Park?
You can call (360) 378-2044. The park office can confirm RV site availability, hookups, length limits and current conditions.
Are there RV campgrounds near Posey Island State Park?
Yes. The closest RV-friendly campgrounds listed on ParkedRV are:
- Douglas Fir Campground (60.5 mi, reservable)
- Excelsior Group Camp (64.5 mi, reservable)
- Boulder Creek Campground (67.6 mi, reservable)
How current is this information about Posey Island State Park?
This listing was last updated on October 8, 2026. If something is out of date, let us know and we'll fix it.