The state park occupies a third of the site of the original Fort Townsend built in 1856.

The park includes 3,960 feet (1,210 m) of shoreline on Port Townsend Bay, picnicking and camping areas, 6.5 miles (10.5 km) of hiking trails, and facilities for boating, fishing, and crabbing.

[4][5] The entire garrison was transferred to the American Camp or Camp Pickett on San Juan Island in 1859 during the border dispute called the Pig War.

[6] Reactivated in 1874, the fort continued in use until fire destroyed the barracks in late 1894; it was abandoned in 1895.

The site was retained on the Army rolls until World War II, when it was used as a munitions defusing station.