The Outer Continental Shelf (OCS) consists of the submerged lands, subsoil, and seabed, lying between the seaward extent of the States' jurisdiction and the seaward extent of Federal jurisdiction. The continental shelf is the gently sloping undersea plain between a continent and the deep ocean. The United States OCS has been divided into four leasing regions. They are the Gulf of Mexico OCS Region, the Atlantic OCS Region, the Pacific OCS Region, and the Alaska OCS Region. In 1953, Congress designated the Secretary of the Interior to administer mineral exploration and development of the entire OCS through the Outer Continental Shelf Lands Act (OCSLA). The OCSLA was amended in 1978 directing the secretary to:

• conserve the Nation's natural resources;
• develop natural gas and oil reserves in an orderly and timely manner;
  
• meet the energy needs of the country;
  
• protect the human, marine, and coastal environments; and
  
• receive a fair and equitable return on the resources of the OCS.

State jurisdiction is defined as follows:

• Texas and the Gulf coast of Florida are extended 3 marine leagues (approximately 9 nautical miles) seaward from the baseline from which the breadth of the territorial sea is measured.
• Louisiana is extended 3 imperial nautical miles (imperial nautical mile = 6080.2 feet) seaward of the baseline from which the breadth of the territorial sea is measured.
• All other States' seaward limits are extended 3 nautical miles (approximately 3.3 statute miles) seaward of the baseline from which the breadth of the territorial seaward is measured.

Federal jurisdiction is defined under accepted principles of international law. The seaward limit is defined as the farthest of 200 nautical miles seaward of the baseline from which the breadth of the territorial sea is measured or, if the continental shelf can be shown to exceed 200 nautical miles, a distance not greater than a line 100 nautical miles from the 2,500-meter isobath or a line 350 nautical miles from the baseline.