President-elect Donald Trump repeatedly promised during his campaign that increase oil drilling in the United States., which is good news for political leaders in Alaska, where oil is the economic lifeblood and many felt the Biden administration has stymied efforts to boost the state’s dwindling production.

A debate over drilling on federal lands on Alaska’s petroleum-rich North Slope is likely to be revived in the coming months, particularly in the Arctic National Wildlife Refuge, which environmentalists have long sought to protect as one of the nation’s last wild places.

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The issue of drilling on the sanctuary’s coastal plains, which Trump sought to do in his first term, also divides Native Alaskan communities. Some welcome the potential new revenue, while others worry about how it will affect wildlife in an area they consider sacred.

The largest wildlife refuge in the country covers an area in northeast Alaska roughly the size of South Carolina. It has a diverse landscape of mountains and glaciers, tundra plains, rivers and boreal forests, and is home to a variety of wildlife including polar bears, caribou, muskox and birds.

The battle over whether to drill in the sanctuary’s coastal plain along the Beaufort Sea goes back decades. Drilling advocates say development could create thousands of jobs, generate billions of dollars in revenue and stimulate U.S. oil production.

While the US Bureau of Land Management has said the coastal plain could contain 4.25 billion to 11.8 billion barrels of recoverable oil, there is limited information on the quantity and quality of oil. And it’s unclear whether companies will want to risk pursuing projects that could become mired in litigation. Environmentalists and climate scientists have pushed for a phase-out of fossil fuels to avoid the worst consequences of climate change.

The sanctuary lies east of the Prudhoe Bay oil fields and the National Petroleum Reserve-Alaska, where the Biden administration approved the controversial Willow project but also made about half of the petroleum reserve off-limits to oil and gas leasing.

An exploratory well was drilled in the 1980s on lands where Alaska Native companies had rights, but little information has been released about the results.

Still, opening the coastal plain to drilling has been a longtime goal of members of Alaska’s congressional delegation. In 2017, they added language to a tax bill requiring two oil and gas sales by the end of 2024.

The first sale took place in the waning days of the previous Trump administration, but President Joe Biden quickly urged Interior Secretary Deb Haaland to review the leasing program.

That led to the termination of seven leases that had been acquired by the Alaska Industrial Development and Export Authority, a state corporation. Smaller companies gave up two other leases. Litigation is ongoing regarding the terminated leases.

The Biden administration recently released a new environmental review, ahead of the deadline for the second mandatory sale. It proposes to offer what the Bureau of Land Management said would be the minimum acreage allowed under the 2017 law — a proposal that Alaska’s Republican U.S. senators have made a mockery of the law meant to encourage exploration.

There are sharp divisions.

Leaders of the Iñupiaq community of Kaktovik, which is within the sanctuary, support drilling. Gwich’in officials in communities near the sanctuary have said they consider the coastal plain sacred. Caribou they trust calf there.

Galen Gilbert, first director of the Arctic Village Council, said the refuge should be off-limits to drilling. Arctic Village is a Neets’aii Gwich’in community.

“We don’t want to bother anybody. We don’t want anything. We just want our way of life, not just for us, but for our future generations,” Gilbert said.

Leaders in Kaktovik have vowed to fight any attempt by the US Fish and Wildlife Service to designate the lands as sacred. Josiah Patkotak, mayor of North Slope Borough, which includes Kaktovik, said in an opinion piece in October that the land “has never been” Gwich’in territory.

“The federal government must understand that any attempt to undermine our sovereignty will be met with fierce resistance,” he wrote.

Oil is critical to the economic prosperity of North Slope communities, said Nagruk Harcharek, president of Voice of the Arctic Iñupiat, a nonprofit advocacy group whose members include leaders from that region. Responsible development has long existed side by side with a lifestyle, he said.

In a video posted on X by Republican Gov. Mike Dunleavy, Trump said he would work to ensure a natural gas pipeline project long sought by state political leaders is built. Opposed by environmentalists, the project has faltered over the years due to changes in direction under different governors, cost concerns and other factors.

While voters “may not have been head over heels” for Trump, they “realized that his policies, when it comes to resource development, are clearly policies that work to benefit an economy like Alaska’s,” Trump critic U.S. Sen. Lisa Murkowski told reporters.

“So I would anticipate that we would once again see a return to greater economic opportunity through resource development,” she said.

Dunleavy said Trump could undo restrictions placed on the Biden administration for new oil and gas leasing on 13 million acres (5.3 million hectares) of the petroleum reserve. Harcharek’s group sued over the restrictions, claiming the region’s elected leaders had been ignored.

Erik Grafe, an attorney for Earthjustice in Alaska, said the petroleum reserve was not set aside “to get oil out at any cost.” Other important resources must be considered and given protection under the law, he said.

“Oil is not the future and it cannot be,” Grafe said. “The state needs to start thinking about a plan B, post-oil.”