Lake Pontchartrain, << PON chuhr `trayn,` >> is a beautiful lake of brackish (slightly salty) water in southeastern Louisiana. It is 40 miles (64 kilometers) long and 25 miles (40 kilometers) wide, and covers 625 square miles (1,619 square kilometers). It is a major recreational center. The Inner Harbor Navigation Canal connects the lake with the Mississippi River to the south. New Orleans lies between the lake and the river. If the river begins to flood, some of its water is forced into the lake through a channel called the Bonnet Carré Spillway. The excess water drains from the lake into the Gulf of Mexico through a strait called the Rigolets. The Lake Pontchartrain Causeway, which spans the lake, is one of the world’s longest bridges and overwater highways. The bridge is 23.9 miles (38.5 kilometers) long. French colonists in Louisiana named Lake Pontchartrain for the Comte de Pontchartrain, minister of marine under King Louis XIV.
