McMicken Island Marine State Park
🏆🏆🏆🏆 Puget Sound Gem — 11-acre island in southern Puget Sound — boat-access-only camping on a tiny forested island with stunning sunset views
McMicken Island Marine State Park is a tiny 11-acre island in Case Inlet of southern Puget Sound — connected to Harstine Island by a low-tide sandspit that you can walk across! This tombolo (a sand bar connecting an island to the mainland) is exposed for several hours around low tide, creating one of Washington’s most unique park experiences — an island that becomes a peninsula twice a day. The surrounding waters of southern Puget Sound are home to Dungeness crab, geoduck clams (pronounced “gooey-duck”), and Pacific oysters.
Visitor Information
| Detail | Information |
|---|---|
| Location | Case Inlet, Puget Sound, WA |
| Entry Fee | Discover Pass required |
| Size | 11 acres — WALK at low tide! |
| Feature | Tombolo — island→peninsula twice/day! |
About McMicken Island
McMicken Island Marine State Park is a unique tidally-connected island in southern Puget Sound near Harstine Island. At low tide, a gravel tombolo connects McMicken to Harstine Island — you can walk to the island! At high tide, it becomes a true island. The 11-acre park offers excellent shellfish harvesting and Puget Sound scenery.
Things to Do
Walking the tombolo at low tide, shellfish harvesting (oysters, clams — with license), kayaking, beachcombing, and birdwatching. The island has primitive campsites for boaters. The dynamic tidal connection makes every visit different.
Insider Tips
Tombolo island: McMicken Island connects to Harstine Island by a tombolo — a natural sand bridge exposed at low tide. Pro tip: Walk to the island at low tide to explore old-growth forest and rocky shores. South Sound: South Puget Sound’s warmer, shallower waters support different marine life than the colder northern Sound — including Olympia oysters, the only native oyster on the West Coast.
Best Time to Visit
Summer: Best low tides and weather. Spring: Extreme low tides for tombolo crossing. Fall: Oyster season begins. Winter: Storm watching from Harstine Island.
Frequently Asked Questions
What is a tombolo?
A tombolo is a natural sand or gravel bar connecting an island to the mainland (or another island) — exposed at low tide and submerged at high tide. Tombolos form when waves deposit sediment in the sheltered area behind an island. McMicken’s tombolo is one of the best examples in Puget Sound — the tide-dependent crossing adds adventure to any visit.
🏝️ Visit McMicken Island Marine SP
Walk to an island at low tide — tombolo magic in Puget Sound!
Wildlife & Nature
McMicken Island Marine State Park — an 11-acre island in southern Puget Sound’s Case Inlet, connected to Harstine Island by a tombolo (sand spit) walkable at low tide — offers a unique land-and-water park experience. At high tide, it’s an island; at low tide, you can walk to it. Harbor seals haul out on the surrounding rocks. Bald eagles perch in the madrone and Douglas fir trees. The gravel beach reveals clams, oysters, and marine invertebrates. Great blue herons fish the shallows. The island’s small size creates an intimate, uncrowded experience.
Nearby Attractions
Harstine Island — connected at low tide via tombolo — has Jarrell Cove State Park (marine camping). Shelton — 15 miles southwest — provides services. Olympia — 20 miles east — is the state capital. Hope Island State Park — nearby by boat — offers primitive island camping.
