The Energy Information Administration, part of the Energy Department, said crude oil inventories on the Gulf Coast reached 207.2 million barrels April 11, the highest level ever recorded.
EIA said the buildup was a result of the closing of area refineries for routine maintenance, the opening of a new TransCanada pipeline feeding the region and increased crude oil production in the country.
Last week, EIA said proved crude oil reserves in the United States in 2012 were 33 billion barrels, a 15 percent increase from the previous year and the highest level ever recorded since 1976.
EIA said Thursday the main driver of crude oil inventory gains was the January launch of TransCanada's so-called Marketlink pipeline, which runs from Cushing, Okla., to a storage facility in Houston. The pipeline has a capacity to deliver as much as 525,000 barrels of oil per day from the Cushing storage hub.
EIA added an increase in regional crude oil production has kept Gulf Coast inventories elevated.
"In the 106 weeks since March 2012, U.S. Gulf Coast inventories have been above the previous five-year average in all but seven of those weeks," EIA said.