River Parishes

Three of the parishes, St. Charles, St. John the Baptist and St. James, are also part of the New Orleans metropolitan area, based on the U.S. Census Bureau definition.

If Ascension Parish is included, the total land area is 2,694.10 km2 (1,040.198 sq mi) and the census population is 228,345.

Its four largest communities are all unincorporated census-designated places: LaPlace, Luling, Destrehan, and Reserve.

Its two largest incorporated cities are located in Ascension Parish, which may not be considered by some to be within the community: Gonzales and Donaldsonville.

Still smaller in population, however, are the largest incorporated towns in the three-parish area: Lutcher and Gramercy.