The Strategic Petroleum Reserve (SPR) is the world's largest supply of emergency crude oil. The federally-owned oil stocks are stored in huge underground salt caverns along the coastline of the Gulf of Mexico.
Decisions to withdraw crude oil from the SPR are made by the President under the authorities of the Energy Policy and Conservation Act. In the event of an energy emergency, SPR oil would be distributed by competitive sale. The SPR has been used under these circumstances only twice (during Operation Desert Storm in 1991 and after Hurricane Katrina in 2005). Its formidable size (700-plus million barrels) makes it a significant deterrent to oil import cutoffs and a key tool of foreign policy