The U.S. Energy Department's Energy Information Administration reports that U.S. oil production during the first quarter of 2012 topped 6 million barrels per day for the first time since 1998.
"The roughly 6 percent growth in U.S. oil production from October 2011 through March 2012 is largely the result of increases in oil output in North Dakota, Texas and the Gulf of Mexico," the agency said in a statement.
The EIA said Texas and North Dakota are the top oil-producing states in the country.
The EIA information follows an effort in the Republican-controlled U.S. House of Representatives to increase access to the National Petroleum Reserve-Alaska and remove federal burdens to onshore oil and gas leases.
Democratic leaders said the effort is in contrast to recent oil production data and trends in the retail energy market.
The EIA indicated U.S. oil production was steady at around 5.5 million bpd for much of 2011.