A U.S. stockpile of petroleum that was created as a counter measure after the 1973 energy crisis in which an Arab led oil embargo halted oil exports to the United States. As a result, fuel shortages caused significant disruptions in the U.S. economy.

The physical reserves are located underground in four man-made salt domes in Texas and Louisiana. All four locations combined hold a total of 727 million barrels of oil providing roughly 80 days of supply during an emergency. The SPR is currently the largest emergency oil reserve in the world.

Only the U.S. President has the ability to tap the reserves in case of severe energy supply interruption. In 2005, President Bush ordered the emergency sale of 11 million barrels when Hurricane Katrina shutdown 25 percent of domestic production. In 2011, President Obama ordered the release of 30 million barrels to help offset disruptions caused by political upheaval in the Middle East.