Is Posey Island Marine State Park first-come first-served or reservation?

Posey Island Marine State Park accepts online reservations. We recommend booking in advance, especially during peak season (typically summer weekends). Use campsite alerts to get notified when spots become available.

Are there showers at Posey Island Marine State Park?

Posey Island Marine State Park does not have shower facilities. Plan accordingly—nearby alternatives may include day-use areas or towns.

Can I have a campfire at Posey Island Marine State Park?

Fire policies at Posey Island Marine State Park: A fire ring is present at one campsite per trip reports; follow Washington State Parks fire restrictions and bans (specific policy details not provided).. Always check current fire restrictions before your trip, as conditions change seasonally.

How many campsites does Posey Island Marine State Park have?

Posey Island Marine State Park has 2 campsites. Sites vary in size, privacy, and amenities. Check availability online to find the best site for your needs.

Are dogs allowed at Posey Island Marine State Park?

Pets are not allowed at Posey Island Marine State Park. This policy helps protect local wildlife and other campers. Consider nearby pet-friendly campgrounds if traveling with animals.

What activities can I do at Posey Island Marine State Park?

Popular activities at Posey Island Marine State Park include Fishing, Swimming, Boating, Wildlife Viewing. The surrounding area offers plenty of outdoor recreation opportunities for all skill levels.

Posey Island Marine State Park

5 reviews

Scenic Views

Featured in:Fishing Camping Washington

Real-Time Availability

Select a month, then check for open campsites

Quick Facts

Price

Varies

Booking

Reservable

Sites

2 campsites

Season

Year-round

Cell

Unknown

Pets

Check Policy

Book on Washington State Parks Set up a cancellation alert Official Website

Get Directions

Only 2 sites — this campground fills fast. Set up a free alert.

Real-Time Availability

Select a month, then check for open campsites

Quick Facts

Price

Varies

Booking

Reservable

Sites

2 campsites

Season

Year-round

Cell

Unknown

Pets

Check Policy

Book on Washington State Parks Set up a cancellation alert Official Website

Get Directions

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...

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

N/A

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."

Read all reviews

Campground Map

Posey Island Marine State Park

48.6188, -123.1681

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

Early fall delivers the best conditions. Daytime highs run mid-50s to mid-60s°F (12–18°C), with cool evenings and calmer seas than summer. Boat traffic drops after Labor Day, and wildlife viewing stays strong through September and October. Clearer skies improve paddling and photography before winter storms arrive. Summer brings more visitors and wind. Check marine forecasts and tides before any trip. The island's exposure makes conditions variable.

Best

Fall(Sep-Nov)

4.5 / 5

Top 8% in WA

Early fall cited as best: calmer seas, cooler temps, and less day‑boat traffic.

Planning Tips

About Posey Island Marine State Park

Posey Island Marine State Park sits on a one-acre island in the Haro Strait, accessible only by boat. The park offers two primitive tent sites for kayakers and paddlers, with a composting outhouse, fire rings, and picnic tables. Motorboats are day-use only. Overnight visitors need human- or wind-powered craft.

Small, primitive marine campsite setting with two reserved group sites on a tiny one‑acre island; boat‑in only.

Weather and SeasonsEarly fall delivers the best conditions. Daytime highs run mid-50s to mid-60s°F (12–18°C), with cool evenings and calmer seas than summer. Boat traffic drops after Labor Day, and wildlife viewing stays strong through September and October. Clearer skies improve paddling and photography before winter storms arrive. Summer brings more visitors and wind. Check marine forecasts and tides before any trip. The island's exposure makes conditions variable.

Natural Features and SceneryThe island features gravel beaches, meadow openings, and fir trees that provide shade at the campsites. Sunset views across the Salish Sea draw frequent praise from visitors. Seals, seabirds, and regular whale activity animate the surrounding waters. Beachcombing along the rocky shoreline turns up driftwood and tidal finds. The exposed location means wind is common, especially on the more open site. Night skies are dark and clear for stargazing when weather cooperates.

Geological RegionSan Juan Islands (Haro Strait), Salish Sea

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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.

Fishing

Swimming

Boating

Wildlife viewing

Planning your trip?Check out our camping packing checklist

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.

No Flush ToiletsFlush toilets are not available at this campground. Expect vault or pit toilets only.

No Electric HookupsElectric hookups are not available at this campground. RV campers should arrive with a full battery and plan for off-grid power (generator hours/quiet rules permitting).

No Water HookupsSite-level water hookups are not available. RV campers should fill freshwater tanks before arrival; check the No Potable Water note above if applicable for drinking water.

No Dump StationThere is no dump station at this campground. Plan to use a dump station along your route or at a nearby facility before or after your stay.

Weather at Posey Island Marine State Park

Trip Planning Tools

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Reviews

From Booking Sources

0.0

5 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...

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...

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...

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...

Based on 5 reviews

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Jones Island Marine State Park

Washington State Parks, Washington

Jones Island Marine State Park sits in the San Juan Channel near the Wasp Islands, accessible only by boat. The park has 11 primitive tent sites, including two Cascadia Marine Trail sites on the quieter west shore. Sites cost $12 per night. Potable water runs mid-May through mid-September; outside that window, you pack your own.