Gulf Coast of the United States Pensacola, St. Petersburg, Tampa, and increasingly, Sarasota. All are the centers of their respective metropolitan areas and contain large ports. (Baton Rouge is relatively far from the Gulf of Mexico; its port is on the Mississippi River, as is the port of New Orleans.) The Gulf Coast is made of many inlets, bays, and lagoons. The coast is also intersected by numerous rivers, the largest of which is the Mississippi River. Much of the land along the Gulf Coast is, or was, marshland. Ringing the Gulf Coast is the Gulf Coastal Plain which reaches from Southern Texas to the western
Gulf of Mexico ago as a result of plate tectonics. The Gulf of Mexico basin is roughly oval and is approximately wide and floored by sedimentary rocks and recent sediments. It is connected to part of the Atlantic Ocean through the Florida Straits between the U.S. and Cuba, and with the Caribbean Sea (with which it forms the American Mediterranean Sea) via the Yucatán Channel between Mexico and Cuba. With the narrow connection to the Atlantic, the Gulf experiences very small tidal ranges. The size of the Gulf basin is approximately 1.6 million km (615,000 sq mi). Almost half of the basin is