A subtly worded instruction in the just-released House budget could provide a path for drilling in the Arctic National Wildlife Refuge—one of the last truly untouched places in America.

The coastal plain of ANWR, a 1.5-million-acre stretch along the northern coast of the refuge, has long been in dispute. For decades, advocates of oil and gas drilling have proposed opening it for development, but each attempt has been fought off. Now, with a Republican Congress and a president who enthusiastically backs Arctic drilling, the effort appears more likely than ever to pass.

The budget includes an assumption of $5 billion in federal revenue from the sale of leases over the next 10 years, and instructs the House Natural Resources Committee to come up with a plan to generate that amount of money.

Though it doesn’t explicitly direct the committee to look to ANWR for those funds, that is the clear implication, said Sierra Club legislative director Melinda Pierce. “I don’t think there’s any confusion among anyone that this is directed at opening the Arctic National Wildlife Refuge to drilling,” she said.

The House budget instructs the Natural Resources Committee to move the bill through what’s known as the budget reconciliation process, which would mean the Senate could pass it with just a simple majority. It’s not the first time this has been attempted. In 1995, a reconciliation bill recommending opening ANWR made it through Congress, only to be vetoed by President Bill Clinton. It was introduced again in 2005, but didn’t make it out of the Senate.

“This is a shameless attempt to push an extremely unpopular action through the back door of Congress on behalf of President Trump and the oil lobby,” said Drew McConville, senior managing director for government relations for The Wilderness Society, in a statement. “This refuge is a national treasure, and we have a moral obligation to protect it for future generations of Americans. It is simply too special to drill.”

“The Sacred Place Where Life Begins”

The 19.6 million acres of ANWR were first protected by President Dwight Eisenhower in 1960 before receiving additional protections from Congress in 1980. But when the wilderness designation was made, it was left to Congress to decide at a later date whether the tundra of the coastal plain should be opened up for oil and gas exploration. It’s been fought over ever since.

The coastal plain is the historical home of the Gwich’in people and is the spot where each year a herd of nearly 200,000 caribou travel to birth their young. It’s around this time each year that the herd begins its journey south, with thousands of new calves in tow. They wander across the remote wilderness of the refuge, travelling thousands of miles during their annual migration.

“This area is known to us as ‘Iizhik Gwats’an Gwandaii Goodlit’ – the sacred place where life begins,” said Bernadette Demientieff, Executive Director, Gwich’in Steering Committee. “For us, protecting this place is a matter of physical, spiritual and cultural survival. It is our basic human right to continue to feed our families and practice our traditional way of life.”

Iconic Frontier Draws Bipartisan Support 

Though passage via a reconciliation bill is by far the easiest path to opening up ANWR, it’s not a done deal just yet. Historically, opposition to drilling in the region has been bipartisan, said Alex Taurel, the deputy legislative director of the League of Conservation Voters. “This is a hugely controversial provision with the American people,” he said.

A December 2016 poll by the Center for American Progress found that 43 percent of Trump voters oppose drilling in ANWR and 29 percent strongly oppose it. Among voters for Hillary Clinton, that jumps to 87 percent opposing it, and 72 percent strongly opposing it.

“I think, at the end of the day, it’s not going to work,” said Pierce. “They’re banking on the Senate having the 51 votes to pass a reconciliation package that includes Arctic drilling. … I think they’re underestimating the iconic value of Alaska and the frontier.”