Empirically, US companies have leased and developed oil development claims on ECS since 2001 without needing UNCLOS framework

Reality tells a different story. The ECS area on the U.S. portion of the western gap has been available for development since August 2001. Specifically, the Bureau of Ocean Energy Management (BOEM)²² offered the northern portion of the western gap for lease almost immedi- ately after the 2000 U.S.–Mexico ECS delimitation treaty was ratified. That treaty entered into force on January 17, 2001. Seven months later, on August 22, BOEM offered the area of U.S. ECS in the western gap in Lease Sale 180. In that lease sale, three U.S. companies (Texaco, Hess, and Burlington Resources Offshore) and one foreign company (Brazil’s Petrobras) submit- ted successful bids totaling more than $2 million for seven lease blocks in the western gap.²³ BOEM has offered the ECS blocks in the western gap in 19 lease sales between August 2001 (Lease Sale 180) and March 2010 (Lease Sale 213). In connection with those sales, seven U.S. companies (Burlington, Chevron, Devon Energy, Hess, Mariner Energy, NARCA Corporation, and Texaco) submitted bids to lease blocks in the western gap. Five foreign companies—British Petroleum, Eni Petroleum (Italy), Maersk Oil (Denmark), Petrobras, and Total (France)—also bid on western gap ECS blocks during those sales. BOEM collected more than $47 million in bids in connection with lease sales on those blocks.

Of the approximate 320 blocks located in whole or in part on the western gap ECS, 65 (approximately 20 percent) are currently held under active leases by nine U.S. and foreign oil exploration companies.²⁴

The successful delimitation and subsequent leasing of areas in the Gulf of Mexico demonstrate that the United States does not need to achieve universal international recognition of its ECS. The United States identified and demarcated areas of ECS in the western gap in cooperation with the only other relevant nation, Mexico, and that area was subsequently offered for development to U.S. and foreign oil and gas companies.²⁵ All of this was achieved without U.S. accession to UNCLOS or CLCS approval.