Clio Logo

The Plaquemine Lock was completed in 1909 and was designed by Colonel George Goethals, who would later become famous for designing the Panama Canal. When it was completed, the lock was the highest freshwater lock in the world. It's located across the street from the Iberville Museum. Plaquemine Lock is operated between the Louisiana Department of Culture, Recreation & Tourism, the City of Plaquemine and the Iberville Parish Tourism Department. Site features include a short film, guided tour of the lock house, view of the Mississippi River and lock chamber, and several examples of boats used along the Atchafalaya Basin.


  • The path leading up to Plaquemine Lock. Credit: Iberville Parish Tourism Department
  • The Plaquemine lock connected the Mississippi River to Bayou Plaquemine. The lock was designed for differences in water level as high as fifty feet from the river at flood stage to the bayou. Credit: Flickr user Dan Troyka

The Plaquemine Lock was designed by Colonel George W. Goethals (1858-1928), the assistant to the chief engineer of the U.S. Army Corps of Engineers. Goethals later gained distinction as chairman and chief engineer of the Isthmian Canal Commission for the design and construction of the Panama Canal.

When completed in 1909, the lock was significant for having the highest freshwater lift of any lock in the world at 51 feet and a unique engineering design that used a gravity flow principle. The gates were later modernized by the installation of hydraulic pumps. The lock served its purpose well by providing a shortcut from the Mississippi River into Louisiana’s interior. By 1925, Bayou Plaquemine had become the northern terminus of the Intracoastal Canal system.

As a distributary of the Mississippi River and a route to the heartland of Louisiana through the Atchafalaya Basin, Bayou Plaquemine was used as navigable artery centuries before the age of European exploration. From the early 1700s, Bayou Plaquemine served as a commercial transport route, promoting settlement and economic prosperity in southwest and northern Louisiana via the Atchafalaya, Red and other rivers.

Increased river traffic during and after World War II put a severe strain on the lock’s capacity and demand increased for a larger lock at Port Allen. In 1961, a larger set of locks began operating at Port Allen and the Plaquemine Lock was closed after 52 years of service. Thirteen years after closing the lock, the Corps of Engineers supervised the construction of the present levee across the mouth of Bayou Plaquemine at the Mississippi River, giving the historic old structure greater stability and providing flood protection, while closing off access to the Mississippi River through Bayou Plaquemine.

In 1972, the Plaquemine Lock structure was placed on the National Register of Historic Places. In addition to the lock, the area includes the Gary James Hebert Memorial Lockhouse, which serves as a museum and visitors center. Hebert worked to prevent the destruction of the lock by the Corps of Engineers and campaigned to have the area preserved as a historic site. Facilities also include a stylized adaptation of the Lockmaster’s house which provides open-air pavilion space to display various water craft used when the lock was operational.

Plaquemine Lock Historic Site. Louisiana Travel. Accessed March 20, 2018. https://www.louisianatravel.com/articles/plaquemine-lock-state-historic-site. 

Plaquemine Lock Historic Site. Plaquemine. Accessed March 24, 2018. https://www.plaquemine.org/194/Plaquemine-Lock-State-Historic-Site. 

Plaquemine Lock Historic Site. Teaching History. Accessed March 23, 2018. http://teachinghistory.org/history-content/historical-site/6910.

Plaquemine Lock Historic Site. Visit Iberville. Accessed March 24, 2018. http://www.visitiberville.com/attractions/plaquemine-lock-historic-site/.

Plaquemine Lock State Historic Site. Louisiana Department of Culture. Recreation and Tourism. Accessed March 29, 2018. https://www.crt.state.la.us/louisiana-state-parks/historic-sites/plaquemine-lock-state-historic-site....