Fort Casey was a coastal defense fort on the western side Whidbey Island at Admiralty Head directly west of Admiralty Bay in western Island County. In 1897, when established, it had ten batteries of coast artillery and was inactivated in 1950. It is now a Washington State Park and has with two restored guns. It was named by army officials for Brig. Gen. Thomas Lincoln Casey, once Chief of Engineers, U.S. Army whose father Silas Casey once commanded Fort Steilacoom.