The United States stores its emergency oil supply in massive, man-made salt caverns.

Countries & Cities · Published 29 September 2026 Swipe more like this →

In short: Deep beneath the Gulf of Mexico, the U.S. maintains the world's largest publicly known emergency petroleum stockpile. Rather than building expensive steel tanks, the government dissolves salt domes with water to create vast, cost-effective caverns. This underground reserve acts as a critical buffer against global energy supply disruptions.

Established in 1975 following the 1973–1974 oil embargo, the Strategic Petroleum Reserve (SPR) was designed to mitigate future supply shocks. The system currently consists of four sites in Louisiana and Texas, where oil is stored in artificial caverns created by drilling into salt domes. This method is roughly ten times more cost-effective than surface storage, offering the added benefits of temperature-driven natural oil circulation and enhanced leak protection.

The reserve is managed by the Department of Energy, with its administrative office located in Elmwood, Louisiana. While the facility's total capacity is 714 million barrels, actual inventory fluctuates based on market conditions, congressional mandates, and emergency drawdowns. For instance, the 2022 release of 180 million barrels was the largest in the program's history, dropping levels to a 40-year low. These sales are often controversial, with some administrations using them to influence fuel prices, while others have faced legislative blocks when attempting to refill the reserve during market downturns.

The SPR is strictly a crude oil reserve, not a stockpile of refined products like gasoline or diesel. In the event of a major refinery disruption, the U.S. would rely on international partners or foreign refining capacity. As a founding member of the International Energy Agency, the U.S. is committed to maintaining stocks equivalent to at least 90 days of net imports. While the reserve provides a significant safety net, its future size remains a subject of debate, with some reports suggesting that lower import needs justify a smaller, more efficient stockpile.

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