WASHINGTON — The federal government has opened 229 million acres of Western lands to oil and gas drilling over the last 22 years, of which 45 million acres were added during President Bush's administration, according to a report released Wednesday by the Environmental Working Group.

Despite this, the nation's dependence on foreign oil has nearly doubled in that time, according to the conservation advocacy organization.

In pushing for more oil and gas extraction in the West and Alaska and for rollbacks of environmental regulations that restrict it, the Bush administration has argued that domestic sources of energy must be tapped if the United States is to overcome its dependence on foreign fuels.

Vice President Dick Cheney said at an Arkansas town meeting this month that the United States needs to use domestic sources to meet ever-expanding demand, but that "we've taken large chunks of the country and put (them) off-limits to any kind of exploration or development.''

Between 1993 and 2000, the Clinton administration banned oil and gas drilling on 64 million acres in the West.

The environmental group cited political contributions by oil and gas corporations, noting in its report that they exceeded $75 million since 2000, with 79 percent going to Republicans. The report argued that an area greater than Arizona, Colorado and New Mexico combined is open to energy companies, but without significant result.

"The oil and gas companies make a profit from these leases, but the energy produced is relatively small,'' said Working Group analyst Dusty Horwitt.

He cited government studies showing that the five richest oil-and-gas basins in the West contain, at most, a 279-day of supply of oil and an eight-year supply of natural gas.

In the period covered by the group's report, net imports of foreign oil rose to 11.2 million barrels last year from about 4.3 million barrels a day in 1982. Fifty-six percent of oil consumed annually in the U.S. is from foreign sources, up from 28 percent in 1982, the report found.