WASHINGTON -- The three-decade-long fight over whether oil companies should be allowed inside the Arctic National Wildlife Refuge is taking on a new wrinkle that could lock up the refuge for good.

The wrinkle is the idea of declaring the refuge's coastal plain -- a swath coveted by environmentalists and oil companies alike -- a wilderness, which would place it off-limits to development.

That idea is under consideration as the U.S. Fish and Wildlife Service updates its plan for managing the 19.6 million-acre refuge in the northeast corner of Alaska.

Fish and Wildlife has launched a two-year revision of its plan and is now taking public testimony on what the refuge's future should be.

The South Carolina-sized refuge is composed of three parts. The southern half is designated as a refuge. Above that is an 8 million-acre mountainous section that is wilderness. And north of that lies the 1.5 million-acre coastal plain -- an area a little larger than the Municipality of Anchorage that Congress set aside in 1980 for further study.

Those who lead Alaska and who represent the state in Washington, D.C., argue the coastal plain holds billions of barrels of oil, making it one of the nation's best prospects for new onshore oil discoveries. Its development, they argue, could provide additional energy security for the nation as well as drive Alaska's economy for years to come.

Environmentalists note that the coastal plain -- a calving ground for a massive caribou herd -- and the rest of ANWR are unlike any other part of the American landscape, arguing they should be a wilderness, unspoiled by man.

CLASHING VOICES

The voices of both sides were present at a Interior Department hearing Tuesday in Washington. The hearing is part of the two-year Fish and Wildlife review of ANWR's management that includes the controversial question: Should the agency recommend that Congress designate more of the refuge as wilderness, including the coastal plain?

For those who want to see the refuge remain undeveloped, the answer is yes.

"Our members are dedicated conservationists," said David Jenkins of Republicans for Environmental Protection.

"They see oil drilling in Prudhoe Bay and Alaska's North Slope, and they know that vast expanses of Alaska's Arctic have also been made available for such development," Jenkins said. "They've come to the same conclusion the Eisenhower administration came to 50 years ago (when it created ANWR): that protecting the Arctic refuge provides much-needed balance."

But most Alaskans believe the coastal plain should be developed, countered Carl Portman of the Resource Development Council for Alaska.

"In all due respect, we do not need more wilderness in Alaska to sufficiently protect it," Portman said at the hearing. "We can have oil and gas development in a very small area of ANWR while maintaining the very special value of the refuge."

IS A NEW VISION NEEDED?

Although much of the focus of the hearing was on whether to allow oil and gas development in the coastal plain, Fish and Wildlife Service officials emphasized Tuesday that their aging refuge management plan needs updating regardless of the wilderness question. The last plan, completed in 1988, doesn't address a number of emerging issues at the refuge, including the effects of climate change.

The agency also said the old plan fails to take into account a state-federal subsistence management program or the opening to the public of the Dalton Highway, the gravel road linking Interior Alaska to the North Slope oil fields west of ANWR.

"It's time to ask the public what their vision for the future of the Arctic is," said the refuge's manager, Richard Voss. "It's time to take a longer look ahead, basically."

Their goal, Voss said, is to determine whether they're meeting the wildlife and natural diversity management mandates of the refuge as well as their responsibilities as wilderness stewards.

The Fish and Wildlife Service has proposed a vision statement that concludes with this concept: "Through responsible stewardship, this vast wilderness is passed on, undiminished, to future generations."

THE WHITE HOUSE POSITION

If the Interior secretary ultimately recommends that Congress designate the coastal plain as wilderness, changing that designation later would be difficult at best.

There is little precedent for retracting wilderness designations by Congress.

It remains unclear whether the White House is interested in additional wilderness protection, but the Fish and Wildlife Service emphasized Tuesday that politics won't have anything to do with their decision. The agency is working on its own timetable and is in the midst of updating all the master plans for Alaska refuges.

Last month, though, Interior Secretary Ken Salazar reiterated the Obama administration's overriding approach to ANWR. It "is not on the map for exploration or development," Salazar said at the time. "It never has been under President Obama and it hasn't been for me as secretary of Interior."

Alaska's congressional delegation submitted a joint letter Tuesday objecting to any additional wilderness designations. Any study of the future management of the refuge should also include the oil and gas potential of the coastal plain, said Sen. Mark Begich, D-Alaska.

"The last time they had exploration of any kind was 1988," Begich said. "If they're going to do this study, they should have that as part of the equation."

Begich also is working within the Senate Budget Committee to shift funding for the study away from the Fish and Wildlife Service. Instead, Begich said, he'd prefer the money go to the U.S. Bureau of Land Management for a long-needed survey of public lands that are part of settlement claims by the state and Native Alaskans.

Alaska Gov. Sean Parnell is expected to submit his objections at the May 11 hearing in Anchorage, said John Katz, who represents the governor's office in Washington, D.C. The governor's office believes "the coastal plain has been studied and restudied," Katz said, and should be open to exploration.

"We believe the oil and gas resources can be developed safely using the best available technology," Katz said.