Citing a need for domestic energy, the government plans to open for exploratory drilling thousands of acres on Alaska's North Slope (search) that have been protected for decades because of migratory birds and caribou.

The Bureau of Land Management (search) has concluded that oil and gas exploration in the northeastern corner of the National Petroleum Reserve-Alaska can be conducted with "minimal impact" on the area's wildlife.

While most of the 22 million-acre reserve is open to oil development, its lake-pocked northeastern corner has been fenced off, dating back to the Reagan administration, because of environmental concerns. That area also is viewed as having the highest oil and gas potential within the reserve.

Interior Secretary Gale Norton (search) is expected to sign off on the BLM's recommendation next week, said a department official, speaking on condition of anonymity because a final action has not been announced.

The NPRA, which was created in 1923 specifically to have access to oil if needed, is not to be confused with the Arctic National Wildlife Refuge (search) farther to the east, which has been the focus of intense debate in Congress over oil development.

The Fish and Wildlife Service, which like the BLM is part of the Interior Department, has said the area around Lake Teshekpuk in the northeast corner of the NPRA is among the most important molting areas in the entire Arctic for wild geese. It is also used for calving and insect relief by herds of caribou.

The BLM, however, has concluded that more than 400,000 acres surrounding Lake Teshekpuk should be opened for exploratory drilling with restrictions. The government estimates the area contains about 2 billion barrels of economically recoverable oil and 3.5 trillion cubic feet of natural gas.

Henri Bisson, the BLM's Alaska director, outlined the planned action in a speech posted Friday on the agency's Web site, predicting the decision will prompt strong criticism from environmental activists and a likely lawsuit.

"I have been told flat out ... to expect an all out fight to the finish to keep this from happening," said Bisson in the speech, given earlier this week to a business group in Anchorage.

The Anchorage Daily News reported on Bisson's speech Friday.

Bisson called the decision to open the northeastern corner "one of the most difficult projects that we have attempted yet at BLM" but said the reason was simple: "The country needs access to its oil and gas resources and this area is a petroleum reserve."

A broad section of environmentalists and conservationists, from the Wilderness Society to Ducks Unlimited, have urged continued protection of the lake region, noting that almost all of the NPRA already is available to oil companies.

"You do need to have oil and gas development in the NPRA, but not on every single acre," said Eleanor Huffins of the Wilderness Society in Alaska. She said environmentalists have little confidence that the government restrictions will be protective.

"When industry asks for exemptions they give it to them," she said in a telephone interview from Anchorage.

Bisson said the development plan would identify seven lease tracts, of 46,000 to 59,000 acres each, north of Teshekpuk Lake, including 217,000 acres of key habitat for waterfowl. Exploratory leases also will be made available for 157,000 acres east and south of the lake, the area used by caribou.

He said ice roads, graveled drilling pads and other facilities would be limited to 300 acres, excluding pipelines, and exploration would be restricted to winter months, resulting "in minimal impact to the wildlife resources that live in this area."

However, if oil is found — as it widely expected — year-round production will follow, environmentalists said.

Most of the federal petroleum reserve was opened for oil drilling during the Clinton administration, although then-Interior Secretary Bruce Babbitt fenced off 840,000 acres, including the area around Lake Teshekpuk. Norton expanded drilling in the reserve last year, but also left the northeastern section alone.