The last load of fill was dumped on the Strait of Canso. The causeway construction required over 1,385 metres of rock-fill, in waters of a maximum depth of 65 metres. The official opening took place on August 13, 1955. The word Canso was believed to be derived from the Mi’kmaq word kamsok, which meant “opposite the lofty cliffs.” (Also see ‘The Canso Causeway…,’ May 13, 1955.)