National strategic petroleum reserve.

The Strategic Petroleum Reserve is intended to reduce the vulnerability of the United States to interruptions in the oil supply from foreign sources. Storage for 248 million barrels of crude oil in salt caverns and mines, with equipment for pumping and distribution, was constructed and operationally tested in a 4-year period. Its present inventory is the largest known crude oil reserve in the world. Facilities for expanding the reserve's capacity by another 290 million barrels are being developed by solution-mining in salt domes.