Plaquemine Lock State Historic Site, Historic lock and engineering site in Plaquemine, United States.

Plaquemine Lock is a disused lock built between 1895 and 1909 to reconnect the Mississippi River with Bayou Plaquemine. It has a freshwater lift of 51 feet, the highest in the world when completed. A surviving pump house stands on the south side of the lock.

The lock was designed by Colonel George Washington Goethals and began operating in 1909 before closing in 1961. Goethals later became famous for his work on the Panama Canal.

The on-site museum is the Gary James Hebert Memorial Lockhouse, named for the man who led efforts to preserve the site. Bayou Plaquemine, the waterway the lock served, drew settlers from the 18th century and linked southwestern Louisiana and Texas to the Mississippi through the Atchafalaya Basin.

The site is located on Main Street in Plaquemine and operates Thursday through Saturday. Plan to spend time walking around the outdoor grounds and wear comfortable shoes for your visit.

The lock's 51-foot lift made it the highest freshwater lift in the world when it opened in 1909. Its designer, Colonel George Washington Goethals, went on to serve as chief engineer of the Panama Canal and first governor of the Canal Zone. The site covers 19 acres, and the lockhouse is named for Gary James Hebert, who led efforts to preserve it.