Gulf Coast Geography

In 1951, just four years after a major but unnamed hurricane struck what he called the “Gulf Coast Country,” Mississippi writer Hodding Carter Sr. described the area as “a soft, near-tropic abode of chameleon sea and white sand.” The natural elements he described—“the rustling beauty of tall pines and moss-drenched water oaks and redolent magnolias”—contribute to the breeziness of quotidian life on the Mississippi Gulf Coast. But the gentle sea lapping the coast periodically changes more than just its color, rising up like an angry dragon—twice so far since his observation, by Hurricanes Camille (1969) and Katrina (2005)—and slapping at the foundations of coastal life. Since the Mississippi Gulf Coast runs east-west for forty-four miles slightly north of 30 degrees north latitude, and because of its south-facing situation on the east side of a landmass near semitropical waters, it is subject to tropical storms, including hurricanes, churning northward from the Atlantic tropics, sometimes blasting over the West Indies and roiling through the Caribbean Sea and Gulf of Mexico.

Regions lie nested within larger regions. Such is the case with the coast, which is part of the large physiographic province known as the Gulf-Atlantic Coastal Plain (sometimes Atlantic Coastal Plain) that stretches from the middle Rio Grande Valley, in Texas, to southern New Jersey and even Long Island, New York. This large physiographic province is divided into Upper and Lower Coastal plains. The Mississippi section constitutes a portion of the seaward edge of the Lower Coastal Plain, which is made up of two physiographic subregions, the Coastal Terrace and the Barrier Islands. Beyond the barrier islands to the south lie the Continental Shelf and the Gulf of Mexico. Between the barrier islands and the coast is the narrow and shallow body of saltwater (a lagoon) called the Mississippi Sound. Thus, the coast as a natural region is the seaward edge of the Lower Coastal Plain, itself the seaward section of the wide Gulf-Atlantic Coastal Plain.

The mainland part of the Mississippi Gulf Coast, the Coastal Terrace, is between five and ten miles wide and made up of lowlands (e.g., the highest elevation in Bay St. Louis is approximately twenty-five feet), bayous, salt marshes, beaches, and rivers and their narrow floodplains running northward. Much of the coastal plain was once covered by shallow seas.

Mississippi’s territory includes five sandy barrier islands, formed between thirty-five hundred and six thousand years ago. From east to west, they are Petit Bois, south of Pascagoula; Horn Island, about twelve miles out and once the haunt of artist Walter Anderson; Ship Island (actually two islands, East Ship and West Ship), which once provided the only deep-water harbor between New Orleans and Mobile; and Cat Island. In addition, there are two near-shore islands: Round, a small island near Pascagoula, and Deer Island, now entirely owned by the State of Mississippi and angling obliquely from within a few hundred meters of the Biloxi beach to about two miles offshore directly seaward of Biloxi Bay. Petit Bois, Horn, and Ship Islands are part of the Gulf Islands National Seashore. The islands, like all barrier islands, are in flux. Littoral drift tends to cause erosion on their eastern ends and build up sand spits on their western ends. In addition, Hurricane Katrina severely damaged the barrier islands’ pine trees, as can be seen on Deer Island viewed from the mainland. Another barrier island, the Isle of Caprice, formerly lay two miles beyond Horn but disappeared into the sound’s waters in 1931–32.

The coast is interrupted by bays and bayous. Toward the east is the Back Bay of Biloxi on the north side of the Biloxi peninsula, and Fort Bayou, forming the northern border of Ocean Springs. They meet and form a T where they merge in Biloxi Bay, an opening to the sound. Toward the west is St. Louis Bay, surrounded by the towns of Pass Christian on the east side and Bay St. Louis and Waveland on the west.

Rivers also intersect the coast. The main rivers, from east to west, are the Pascagoula, said to be the largest nondammed river in the eastern United States; the meandering Tchoutacabouffa and Biloxi, which together flow into Big Lake at the western end of the Back Bay of Biloxi; the Wolf; the Jourdan; and the Pearl, a large river flowing south from Mississippi’s capital city, Jackson, and forming part of the state’s western border. The barrier islands and the discharge of the rivers keep the waters of the Mississippi Sound in conditions of relatively low salinity (about half as much as the Gulf in normal years) and high turbidity.

The Mississippi Gulf Coast is classified as having a moist subtropical climate, with mild winters and hot summers. In a normal year, the area receives between sixty-three inches of precipitation (in the western corner) and sixty-six inches (in the east), some of the highest totals in the continental United States. Nearly all of this precipitation is rain (snow is rare), and it is fairly evenly distributed throughout the year.

Despite the area’s low relief, a surprisingly large number of vegetative habitats may be found within a few miles of the coast. The bayous and rivers add complexity. Habitats include maritime communities typically found on the barrier islands and within a few hundred meters of open ocean on the mainland edge. Tidal marshes are wet grasslands that occur along shorelines and tidally influenced portions of coastal rivers. Wet pine savannas were historically a fire-maintained plant assemblage occurring on the wettest (hydric) soils that overlay perched water tables and consisted of a widely spaced canopy of longleaf pine and diverse understory. The Mississippi Sandhill Crane Wildlife Refuge, in Jackson County, maintains this habitat with controlled burns. Pine flatwoods share flat terraces with wet pine savanna but occupy areas with fewer days of standing water.

The coast comprises a cultural landscape exhibiting traits of the wider Gulf of Mexico culture region overlaid on a natural region on the seaward edge of the Gulf-Atlantic Coastal Plain. Post-Katrina recovery along the entire coast has not been a time of large-scale relocation and risk reduction. Instead, beachfront properties have been rebuilt in Pascagoula, Ocean Springs, and other cities. Casinos have been repaired, and high-rise condominiums are being built in Biloxi, Gulfport, and cities to the west. The continued force of global climate change, with the resulting rise in sea levels and more intense tropical storms, has disturbing implications for the future of the Mississippi Gulf Coast. It is, after all, a low-lying coastal region facing a warm, capricious, chameleon-like sea.

Further Reading

  • Ralph D. Cross and Robert W. Wales, eds., Charles T. Traylor, chief cartographer, Atlas of Mississippi (1974)
  • Alan Strahler and Arthur Strahler, Introducing Physical Geography (2006)

Citation Information

The following information is provided for citations.

  • Article Title Gulf Coast Geography
  • Author
  • Keywords Gulf Coast Geography
  • Website Name Mississippi Encyclopedia
  • URL
  • Access Date July 6, 2020
  • Publisher Center for Study of Southern Culture
  • Original Published Date
  • Date of Last Update April 14, 2018