Moses-Saunders Power Dam, Hydroelectric dam on St. Lawrence River, Ontario and New York

Moses-Saunders Power Dam is a concrete structure that spans the St. Lawrence River between New York and Ontario, controlling water flow between the two regions. The installation includes multiple spillways and turbine chambers built into the main structure.

Groundbreaking took place on 19 August 1954, supervised largely by the U.S. Army Corps of Engineers, with Robert Moses overseeing the American side and Robert Hood Saunders the Canadian; Saunders died in a plane crash in January 1955 before the station bore his name. On 1 July 1958 engineers Otto Holden and J. Burch McMorran detonated 27 tonnes of explosives to breach the cofferdam, and the last generators were commissioned in 1959. The dam was dedicated on 27 June 1959 before Queen Elizabeth II, Richard Nixon and Nelson Rockefeller.

The dam carries the names of Robert Moses, chairman of the New York Power Authority, and Robert Hood Saunders, chairman of Ontario Hydro, who jointly oversaw construction. Saunders died in a plane crash in January 1955, before the station bearing his name was completed. The Lost Villages, six villages and three hamlets flooded for Lake St. Lawrence, are commemorated each year by former residents.

The dam lies between Massena, New York, and Cornwall, Ontario; the international bridge on Highway 2/138 crosses the river nearby. The powerhouse and control room are working facilities, so expect security fencing and no public entry. The Long Sault Dam and the Lost Villages museum area give alternative views of the seaway infrastructure.

The facility includes specialized passages for American eels that allow them to complete their annual migrations. These channels were specifically engineered to protect this fish population despite the dam's presence.