About 600,000 sq mi · TX, LA, MS, AL, FL · about 1,630 miles of US coast · Mississippi delta
Gulf of Mexico map
The Gulf of Mexico is the sea south of the United States, bounded by five US states from Texas to Florida, Mexico and Cuba. The Mississippi, Rio Grande and thirty other rivers drain into it.
Where the Gulf is
The Gulf of Mexico is an almost enclosed basin of about 600,000 square miles. Its US shore runs about 1,630 miles from the mouth of the Rio Grande at Brownsville, Texas, around the coasts of Louisiana, Mississippi and Alabama to the Florida Keys at the southern tip of Florida. Mexico holds the western and southern shores, and Cuba closes the southeast. Water enters through the Yucatán Channel and leaves through the Straits of Florida as the start of the Gulf Stream. Since 2025, US federal maps have labelled it the Gulf of America; the international name is unchanged.
The five Gulf states
- Texas — about 370 miles of coast: barrier islands (Padre Island, the longest in the world at about 110 miles), Galveston Bay, Corpus Christi Bay and the Laguna Madre.
- Louisiana — about 400 miles: the Mississippi delta and the widest coastal marsh in the country, losing land at a rate of roughly a football field every hour or two.
- Mississippi — about 45 miles, Gulfport and Biloxi, sheltered by the Mississippi Sound and its islands.
- Alabama — about 50 miles, centred on Mobile Bay.
- Florida — the Panhandle from Pensacola to Apalachicola, the Big Bend marshes, Tampa Bay, and the southwest coast down to the Everglades and the Keys.
Time zones: Texas, Louisiana, Mississippi and Alabama are on Central time. Florida is split: the Panhandle west of the Apalachicola River is Central, the rest of the state is Eastern.
Key measurements
- Area: about 600,000 square miles; deepest point the Sigsbee Deep, about 14,000 ft, in the southwest.
- Continental shelf: very wide off Florida and Texas, which keeps the water shallow and warm and makes the coast vulnerable to storm surge.
- Rivers: the Mississippi (with the Missouri, Ohio and Arkansas behind it), Rio Grande, Sabine, Trinity, Brazos, Colorado (Texas), Mobile, Pearl, Apalachicola and Suwannee. About two-thirds of the contiguous US drains here.
- Hurricanes: Galveston 1900 (the deadliest US natural disaster), Camille 1969, Katrina 2005, Harvey 2017, Michael 2018 and Ian 2022 all came ashore on the Gulf.
Ports and cities
Houston, reached by the 50-mile Houston Ship Channel, is the largest Gulf city and the country's busiest port by tonnage. New Orleans and Baton Rouge on the lower Mississippi, Corpus Christi, Galveston, Beaumont and Port Arthur in Texas, Mobile, Pensacola, Tampa and St. Petersburg are the other major ports. San Antonio is 140 miles inland; Miami is on the Atlantic side of Florida but its western suburbs reach the Everglades. Offshore, the Gulf produces most of the country's offshore oil and gas from platforms off Louisiana and Texas.
How the Gulf shaped the map
Spain held the whole Gulf shore until 1803; the Louisiana Purchase gave the US the Mississippi mouth, the 1819 Adams–Onís Treaty added Florida, and Texas brought the western shore in 1845. Alabama and Mississippi each got a narrow slice of coast when the Gulf shore between the Perdido and Pearl rivers was carved up in 1812–1817, which is why both states are tall and thin with a stub of coastline. The Sabine River became the Texas–Louisiana line and the Perdido the Alabama–Florida line at the coast.
Related maps
- US coastlines — all four coasts.
- Mississippi River · Rio Grande — the two great rivers that end here.
- Gulf Coast states · West South Central · All geography maps.