Soldiers were stationed at Fort Casey from 1899 to 1945. The fort’s 10-inch disappearing guns and other modern weapons were the height of technology in the early 20th century, as were the fort’s plotting rooms, observation stations and communications systems.

Improvements in warships and the rise of the airplane soon rendered these forts obsolete, however. By the 1920s, their effectiveness had waned and, though Fort Casey stayed open for training through World War II, it was decommissioned soon after the end of the war.

Fort Casey is the home of Admiralty Head Lighthouse, which sits 127 feet above the waterway where Puget Sound meets the Strait of Juan de Fuca.

The original light station was built between 1859 and 1860 and, though the buildings that made up the first light station were regularly maintained, the project engineers deemed them inadequate. In 1900, they were moved to another location on the fort. The location of the light station was also moved, as the original site stood in the firing path of a new battery proposed for Fort Casey.

The lighthouse that stands today was finished in 1903, a two-story building of Italianate Revival design, which included the light keeper’s residence. In 1922, the lighthouse was discontinued, after being downgraded in 1919 for its lesser navigational value compared to the lighthouses at Point Wilson and Marrowstone Point.

Washington State Parks acquired Fort Casey in 1955.