Posey Island Marine State Park

Star0
5 reviews
Posey Island Marine State Park

Quick Facts

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Price

Varies

Booking

Reservable

Sites

2 campsites

Season

Year-round

Cell

Unknown

Pets

Check Policy

Opens Washington State Parks site

Official Website
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Real-Time Availability

Select a month, then check for open campsites

February 2026

Real-Time Availability

Select a month, then check for open campsites

February 2026
Posey Island Marine State Park
No fees available
Campsite Fees
Fee information not specified in the provided sources. The park consists of two primitive group campsites; no potable water and limited facilities...
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Standard Site Fee$0.00
Hookup Site Fee$0.00
Premium Site Fee$0.00
Hike and Bike Site Fee$0.00
Group Site Fee$0.00
Food Storage Locker Fee$0.00

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What Campers Say

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Limited Reviews

Based on 5 reviews

14 Google reviews

Most mentioned

viewscleanshadebeach

Some mention

crowded

"Reviews emphasize a beautiful, quiet, classic San Juan Islands kayak campsite with two primitive sites, a composting outhouse, good beach access, and strong paddler appeal. Visitors repeatedly note lack of potable water and limited capacity; many reviewers rate the site very highly for scenery and beachcombing."

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Campground Map

Posey Island Marine State Park

Posey Island Marine State Park

48.6188, -123.1681

Driving directionsBoat-in only. Access by human- or wind-powered watercraft from Roche Harbor and other San Juan Island launch points; no road or dock access on Posey Island.
No road access — island is reachable only by boat. Overnight camping restricted to human- or wind-powered watercraft; motorboats limited to day use.
Nearby supplies
Roche Harbor marina/resort and San Juan Island facilities (launch points and supply locations).

Best Time to Camp at Posey Island Marine State Park

Mother Nature keeps things interesting here—the island's exposed position means wind is a frequent companion, adding drama to your adventure. Visit during shoulder seasons like March for an almost guaranteed private island experience, though you'll want to pack warm layers for those crisp marine breezes. Smart paddlers always check marine weather and tide forecasts before setting out, ensuring your island getaway is memorable for all the right reasons.

Summer(Jun-Aug)
3.5 / 5

Summer offers best weather but small island can feel crowded and remains exposed/windy.

Fall(Sep-Nov)
4.0 / 5

Shoulder seasons are quieter and appealing for paddling and solitude.

Best
Spring(Mar-May)
4.0 / 5
Top 23% in WA

Spring offers wildflower meadow, quieter paddling and good shoulder‑season conditions.

Winter(Dec-Feb)
2.0 / 5

Exposed position and rough seas limit winter access and comfort; winter use is low.

Planning Tips

    About Posey Island Marine State Park

    Escape to your own private island paradise at Posey Island Marine State Park, a jewel-box one-acre retreat in the San Juan Islands accessible only by boat. This intimate marine sanctuary offers just two primitive group campsites where kayakers and paddlers can claim their own slice of wilderness, complete with sweeping views across the Haro Strait and the kind of solitude that makes you feel like a true castaway.
    Small, primitive marine campsite setting with two reserved group sites on a tiny one‑acre island; boat‑in only.
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    Amenities available

    Fire rings
    Picnic tables
    Group Sites

    Activities you can enjoy

    Marine/island activities focused on paddling and beach exploration. Common uses include kayaking, paddleboarding, swimming, fishing, crabbing, bird and marine wildlife viewing, and short walks/beachcombing.
    FishingFishing and crabbing opportunities in the surrounding waters are noted as common activities; fish species and regulations are not detailed here — follow state fishing rules.
    SwimmingBeach access for swimming in the Salish Sea; waters are cold and exposed — use caution.
    Boating
    Wildlife viewing
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    Policies & Safety

    Hazards & AlertsWind exposure and weather; strong currents and tide shifts in nearby channels (notably around Spieden Island) can create challenging crossings. No potable water or garbage service — pack in/pack out required.
    No Potable WaterThis campground does not have potable water on-site. Bring all the water you need for drinking, cooking, and cleaning.

    Weather at Posey Island Marine State Park

    Reviews

    0.0
    5 reviews
    Limited Reviews
    Limited Reviews
    Posey Island Marine State Park has limited reviews, placing it in the bottom % of campgrounds based on reviews
    Reviews emphasize a beautiful, quiet, classic San Juan Islands kayak campsite with two primitive sites, a composting outhouse, good beach access, and strong paddler appeal. Visitors repeatedly note lack of potable water and limited capacity; many reviewers rate the site very highly for scenery and beachcombing.
    Review Summaries
    Based on 5 reviews

    What Campers Love

    Scenic, remote one‑acre island ideal for kayakers and paddlers; clean composting outhouse; gravel beaches, good landing sites, shade from trees, excellent sunset views, and dark night skies for...
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    Based on 5 reviews

    Common Concerns

    • **Very limited capacity and potential crowding**: With only two group sites on a one‑acre island, several sources imply that **summer can feel crowded**, especially when commercial kayak tours stop...
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    Based on 5 reviews

    Pro Tips & Recommendations

    Reserve in advance (only two sites). Pack all drinking water and pack out trash. Arrive by human‑ or wind‑powered craft for overnight stays; motorboats are day‑use only. Choose the more sheltered...
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    Based on 5 reviews

    Camper Quotes

    "Absolutely beautiful. Kids had tons of fun looking at all the little rock crabs on the beach."; "Wonderful park to camp at. There are only 2 campsites and there is one composting toilet in an...
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    Based on 5 reviews

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    Last updated February 2, 2026
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