Fort Flagler was constructed to house 10-inch disappearing guns capable of firing shells over 8 miles.
The park contains the only remaining 'M-1906' rapid-fire gun emplacement in the United States.
During World War II, the fort served as a training center for a clandestine Army unit known as the Ghost Army.
The park's Bluff Trail sits atop steep cliffs that are actively eroding and shifting due to coastal wave action.
A portion of the park served as a prisoner-of-war camp for non-combatant civilian internees during the early 1940s.
Fort Flagler Historical State Park is a 1,451-acre park located on the northern tip of Marrowstone Island, Washington, overlooking Admiralty Inlet. Established as a U.S. Army coast artillery fort in 1897, it served as part of the 'Triangle of Fire' along with Fort Casey and Fort Worden to defend the entrance to Puget Sound. The park contains multiple preserved concrete gun batteries and bunkers that visitors can explore. It features over five miles of hiking trails that traverse forest, meadow, and bluff environments. Camping facilities include 116 sites ranging from standard to full hookup, as well as designated water trail sites for kayakers. The park grounds include historic officers' quarters and housing available for overnight rental. Extensive shoreline access provides views of Mount Baker, Mount Rainier, and passing maritime traffic. The site is listed on the National Register of Historic Places.
The upper observation deck of Battery Wamsley provides an unobstructed panoramic view of the lighthouse and the Puget Sound entrance.
Bring a high-powered flashlight to safely explore the interior of the unlit concrete gun bunkers.
Check the tides before walking the beach, as high tide can shrink the accessible sandy areas significantly.
Carry layers, as the marine air at the tip of the island is consistently windier and cooler than inland areas.
Do not attempt to climb or enter closed, fenced-off sections of the historic batteries due to structural instability.
Some historic buildings and specialized exhibits may operate on limited seasonal schedules; the park itself remains open year-round.
Stay on marked trails to avoid unstable cliff edges; pack out all trash to maintain the park's fragile coastal ecosystem.
