[This paper describes the U.S. offshore oil and gas lease sales conducted by the Department of the Interior since 1954. Several decisions are discussed, including bidding for leases, the government's decision whether to accept the highest bid, the incidence and timing of exploratory drilling, and the formation of bidding consortia. Equilibrium models of these decisions that emphasize informational and strategic issues and that account for institutional features of the leasing program are analyzed, and their predictions compared to outcomes in the data.]