LAKE PONTCHARTRAIN is in southeastern Louisiana, five miles north of New Orleans. The lake is about 40 miles long and covers about 600 square miles. It was connected to New Orleans by canal in 1795, by railroad in 1831, and by ship canal in 1921. The Bonnet Carre spillway connects the lake and the Mississippi River thirty-five miles above the city. Two causeways, twenty-three miles in length, cross the lake and form the longest bridge in the world. In the mid-eighteenth century, Lake Pontchartrain served as a link in the British inside passage to the Mississippi. Later, it became part of the overland route to the north and east.
Colten, Craig E., ed. Transforming New Orleans and Its Environs: Centuries of Change. Pittsburgh, Pa.: University of Pittsburgh Press, 2000.
Cowan, Walter G. New Orleans Yesterday and Today: A Guide to the City. Baton Rouge: Louisiana State University Press, 2001.
Lake Pontchartrain (pŏn´chərtrān), shallow lake, c.630 sq mi (1,630 sq km), 41 mi (66 km) long and 25 mi (40 km) wide, SE La., N of New Orleans. It is linked with Lake Maurepas at its western end and with the Gulf of Mexico at its eastern end through Lake Borgne. Tidal and brackish, the lake forms a popular resort and recreational region. The Bonnet Carre Spillway diverts part of the floodwaters of the Mississippi River into Pontchartrain. Two causeways, each c.24 mi (40 km) long, connect New Orleans with Covington, La.; the long, multispan Pontchartrain Causeway II opened in 1969.