Southeastern Georgia's Lower Coastal Plain is a subregion that encompasses the lowest lying areas of the Atlantic coastal plain in the state, containing barrier islands, marshes, and swampy lowlands, as well as flat plains and low terraces.[1] It differs from Georgia's Upper Coastal Plain in that it is lower in elevation with less relief and wetter soils.[1] The United States Environmental Protection Agency defines the Lower Coastal Plain as an ecoregion, part of the larger, interstate Southern Coastal Plain.[1]
Within the subregion flow the major rivers Altamaha, Ogeechee, Saint Marys, Savannah, Satilla, and Suwannee (all of which, except the Suwannee River, empty into the Atlantic Ocean); the Saint Marys and Suwannee rivers have their origins in the Okefenokee Swamp.
The subregion is synonymous with coastal Georgia,[2] and contains the counties of Atkinson, Bacon, Brantley, Camden, Charlton, Clinch, Echols, Glynn, Lanier, Pierce, Ware, and Wayne, south of the Altamaha River; and Bryan, Chatham, Effingham, Liberty, Long, and McIntosh, north of the Altamaha River.[3][1] The three metropolitan areas are those of Brunswick, Hinesville–Fort Stewart, and Savannah.[4] The largest census county divisions, in the order of decreasing population, are Savannah, Hinesville, Pooler–Bloomingdale, Brunswick, Saint Marys, Tybee Island, Waycross, Jesup, Everett, and Richmond Hill.[5] The total population of the eighteen-county subregion is 726,132 (286,271 south of, and 439,861 north of, the Altamaha River), as of the 2010 U.S. census.[5]