Skip to content
Region
Seattle, Tacoma & South Sound

McMicken Island Marine State Park: Hidden South Puget Sound Gem with Tidal Island Access

McMicken Island Marine State Park offers a unique dual-access experience in South Puget Sound, where visitors can reach this 11.5-acre forested island either by boat or by walking across a natural tombolo during low tide from nearby Harstine Island. This day-use marine park features 1,661 feet of pristine saltwater shoreline, old-growth forest trails, and abundant shellfish beds, providing an intimate island adventure with convenient tidal access for those without watercraft.

McMicken Island Marine State Park Fast Facts

Feature Detail
Location Case Inlet, South Puget Sound, Mason County, Washington
Address Administered via Jarrell Cove State Park
Size 222 acres total (11.5-acre island, 210.5 acres tidelands)
Key Features Tombolo connection to Harstine Island at low tide
Activities Day use only, hiking, shellfish harvesting, boating, kayaking
Shoreline 1,661 feet of saltwater shoreline with sheltered cove
Trail System Short forest loop trail through old-growth trees
Access Boat required or walk via tombolo during low tide
Hours 8 a.m. to dusk
Moorage 5 overnight buoys available
Fees Moorage fees apply

Park Overview

McMicken Island Marine State Park sits in the protected waters of Case Inlet on the east flank of Harstine Island, offering visitors a rare tidal island experience in South Puget Sound. Named after William C. McMicken, Washington Surveyor General from 1873 to 1886, the island features a fascinating natural tombolo that connects it to Harstine Island during low tide periods, allowing pedestrian access for several hours each day. This unique feature makes McMicken Island Marine State Park accessible to visitors without boats, unlike most marine parks in the Washington system.

The island’s thick virgin forest of cedar, fir, hemlock, and Pacific madronas creates a lush canopy over an often impenetrable understory of salal, ferns, and huckleberries. Originally homesteaded in the 1890s by Swedish immigrant Charles Lundquist, who cleared 2 acres at the south end for farming, the island remained in private hands until the state purchased it in 1974 from the Warren family, who had owned it since 1914. The family retained private use of a small southeastern section under agreement with the state.

Activities & Recreation

Activity Details Season Difficulty
Forest Hiking Short loop trail through old-growth forest Year-round Easy
Shellfish Harvesting Abundant clams and shellfish year-round with permits Year-round Easy
Tidal Walking Walk to island via tombolo during low tide Year-round Easy
Kayaking Protected cove with calm water conditions Year-round Easy to Moderate
Boating Five overnight mooring buoys available Year-round Easy to Moderate
Wildlife Viewing Active bald eagle nest and forest birds Year-round Easy

Facilities & Amenities

McMicken Island Marine State Park maintains minimal facilities to preserve its natural character as a day-use destination. The park provides two vault toilets and limited picnic tables distributed around the island, while five mooring buoys offer overnight moorage in the sheltered cove. No potable water, garbage receptacles, or camping facilities are available, requiring visitors to bring all necessary supplies and pack out all waste following Leave No Trace principles. A short forest trail winds through the woods providing access to unexpected views of Mount Rainier visible over the hills of the Key Peninsula to the southeast. The natural tombolo creates the park’s most unique feature, allowing visitors to walk directly from Harstine Island during low tide periods.

Camping & Accommodations

McMicken Island Marine State Park is day use only. No overnight camping is allowed.

Planning Your Visit

McMicken Island Marine State Park operates 8 a.m. to dusk daily, requiring either boat access or timing visits with low tides for tombolo crossing from Harstine Island. Visitors planning to walk should consult tide tables carefully, as the sand bar connection is only exposed during lower tides for a few hours each day. The park is administered as a satellite of Jarrell Cove State Park, with moorage fees charged for the five overnight buoys available in the sheltered cove. Shellfish harvesting requires current permits and adherence to seasonal regulations. No camping is permitted, making this strictly a day-use destination. Winter visitors should be prepared for limited daylight hours and potentially challenging tidal conditions affecting the tombolo crossing.

What to Bring & Know

• Current tide tables essential for planning tombolo crossings from Harstine Island
• All water, food, and supplies as no services are available on the island
• Valid shellfish harvesting permits if planning to dig clams or collect other seafood
• Sturdy footwear for potentially muddy or slippery tombolo crossing conditions
• Pack-in, pack-out mentality as no garbage services are provided

Final Word

McMicken Island Marine State Park provides a rare opportunity to experience true island solitude in South Puget Sound, whether accessed by boat through the sheltered cove or by walking the natural tombolo that connects it to the mainland during low tide.

Gear Up for Washington Weather

Washington trails are wet more often than not, and the right gear makes the difference between a great day out and a miserable one. We recommend KEEN Targhee IV Waterproof Hiking Boots for solid traction on muddy and rocky terrain, a North Face Alta Vista Rain Jacket because you will need it even on days that start sunny, and the REI Co-op Flash 22 Pack to carry your layers, water, and snacks. All three are available in men's and women's versions. (affiliate links)

What to Do

Activities

Beach Exploration
Boating
Crabbing
Fishing
Kayaking
Paddleboarding