Gulf of Mexico numerous bays and smaller inlets. A number of rivers empty into the gulf, most notably the Mississippi River and Rio Grande in the northern gulf, and the Grijalva and Usumacinta rivers in the southern gulf. The land that forms the gulf's coast, including many long, narrow barrier islands, is almost uniformly low-lying and is characterized by marshes and swamps as well as stretches of sandy beach. The Gulf of Mexico is an excellent example of a passive margin. The continental shelf is quite wide at most points along the coast, most notably at the Florida and Yucatán Peninsulas. The shelf
Offshore oil and gas in the Gulf of Mexico (United States) and part of offshore Alabama, since 1995. In March 2010, President Barack Obama announced plans to allow drilling in the eastern Gulf of Mexico, in federal waters greater than from the coasts of Alabama and Florida. In December 2010, following the "Deepwater Horizon" oil spill, the Obama administration reversed its plans to open the eastern Gulf, and imposed a moratorium on new drilling in the eastern Gulf of Mexico for at least seven years. The "Deepwater Horizon" oil spill (also referred to as the BP oil spill, the BP oil disaster, the Gulf of Mexico oil spill, and the Macondo