Buried in the hills of southwest Alaska is a treasure worth as much as half a trillion dollars.

This deposit of minerals and metals, known simply as Pebble, contains the largest untouched reserve of copper in the world — some 80 billion pounds of it — along with thousands of tons of gold.

If you haven’t heard of the Pebble deposit, that’s no surprise. Located 200 miles southwest of Anchorage, it’s accessible only by air, which has helped keep it from the public eye.

But chances are you’re going to start hearing a lot more about it. The Pebble deposit’s fate is one of the biggest environmental decisions facing Barack Obama’s administration since the Keystone XL pipeline.

If approved, it could eventually become the biggest open pit mine in North America, maybe the world. But it’s not just Pebble’s size that has many people upset; it’s the location.

The mine — along with billions of tons of potentially toxic waste — would sit at the headwaters of one of world’s most important salmon spawning grounds. Its critics, like former Republican Alaska state Sen. Rick Halford, believe poisonous runoff is bound to end up in the surrounding rivers and streams.

“The thing that makes this so important is water is everywhere. Water connects everything we’ve got,” explained Halford. “It’s like blood in the human body and it doesn’t take but a tiny infection to poison your whole body.”

But defenders of the proposed mine say there are critical safeguards in place, and that environmentalists are using scare tactics to persuade the public. They also argue the Pebble deposit could bring hundreds of steady jobs to the area, strengthening communities that desperately need it.

‘No ordinary mine’

According to the mining company’s assessment, Pebble would be no ordinary mine. It would require hiring 2,500 construction workers just to get the site up and running. Getting the metal out of the ground means digging a hole that could eventually be more than three miles wide and 4,000 feet deep — more than three times as deep as the Empire State building is high.

Mining company executives have repeatedly assured the public the mine can be built and operated safely. Mike Heatwole, a vice president with the Pebble Partnership, the company that intends to unearth the fortune, told “America Tonight” it has already spent $150 million on environmental studies. Heatwole says those studies have focused on characterizing the ecosystem surrounding Pebble and identifying ways the mine can be built to protect it.

A mine of this size and potential riches, he added, is a plus, not a minus. It means having “the financial resources to do it right.”

Heatwole also argues there are critical safeguards in place, emphasizing that the mine would need more than 50 permits from both federal and state regulators before even being allowed to operate. “Mines have to meet environmental criteria,” he cautioned.

Fishers’ fallout

About 125 miles downstream from Pebble sits the fishing village of Dillingham, the gateway to Bristol Bay, the most prolific salmon fishery in the world. About 2,000 boats work the waters off the bay, catching half a billion dollars worth of fish each year.

Among her fellow captains, 70-year-old Snooks Moore is a legend. She’s been fishing the waters off Alaska since she was a teenager, and despite two knee replacements and a pair of shoulder operations, she’s still going strong.

Moore had a chance to visit the Pebble site as part of a tour the company gave local businesspeople. As Moore puts it, that’s when she came to the conclusion that “these guys are out of their minds.”

During that visit, Moore said company officials assured the group the mine wouldn’t be a threat to salmon waters, as the nearest river was two miles away. Moore wasn’t buying it, pointing to the surrounding lakes and ponds, asking company officials, “Where do you think that water comes from?”

Moore — and pretty much everyone else in Dillingham — considers Pebble a threat to their way of life. Commercial fishing is a trade that has passed from generation to generation, with crews of three or four on each boat. The Pebble Mine, said Moore, “would be the beginning of the end.”

The fishing industry is one of the most powerful groups in Alaska. Along with its allies, it’s spent hundreds of thousands of dollars lobbying against Pebble. The mining company has also spent heavily. But the fishermen have been winning in the court of public opinion: recent polls show that more than 60 percent of Alaskans oppose the mine.

Beyond the clash of industries, the divide over the mine also runs through the native Alaskan community. Each summer, the salmon return to Bristol Bay; each summer native Alaskans come to catch them.

Under a special provision of federal law, several tribal leaders near Bristol Bay asked the Environmental Protection Agency to stop Pebble from going forward, arguing it is a threat to their way of life. Kim Williams was one of them.

“Every mine we’ve looked at, where they’ve had a liner, where they said that no toxic waste will go through this liner, they all leak,” Williams said. “It’s in the wrong location because it is where fish spawn. It’s just bad for Bristol Bay.”

Earlier this year the EPA released a report condemning the proposed mine, arguing it would have “significant and irreversible negative impacts” on the Bristol Bay salmon. As early as this summer, it may propose to ban the mine even before it files for a permit — something the agency has only done twice in its history.

Legislation has been introduced in Congress that would prevent the EPA from taking any preemptive action against the mine. And the mining company — along with the state of Alaska, which supports the mine — has sued, accusing the agency of acting illegally.

If the mining company wins in the courts, “We’ll still fight it,” vowed Williams. “And if I’m not here, my kids will fight it.”

An economic boom?

As strongly as native groups in the Bristol Bay area oppose the mine, others closer to the site support it.

Lisa Reimers likes to remind people that “not everyone goes fishing.” She’s the CEO of the Iliamna Development Corporation, a native-owned company headquartered about 15 miles from Pebble.

“Everybody wants to talk about fish and the environment, which is important,” she said. “But there’s also people who live in these villages.”

The village of Iliamna, with about 100 year-round residents, is typical of the small communities that dot the interior of Alaska. Job opportunities are scarce and winters are brutally harsh, with little opportunity for subsistence hunting or fishing.

Reimers’ company hauls fuel, runs barges and rents construction equipment. It has been the biggest local employer at Pebble, at one point providing more than 100 workers to the site.

According to the Alaska Miners Association, mining jobs in the state pay an average annual wage of $100,000. In short, Pebble — with its hundreds of steady jobs — could make a big impact in the small towns nearby. The mining company has said it will make hiring local residents a priority.

Reimer resents how much of the criticism directed at the proposed mine is coming from environmental groups outside of Alaska, or from well-heeled companies like the sport fishing outfitter Orvis and the jeweler Tiffany and Company. She accuses them of relying on “scare” tactics.

“They’re not talking about the people that live here. The people are the ones that are struggling to survive and pay their fuel, their electricity, the high prices of groceries,” she said. Without the mine, Reimers said, Iliamna “could die.”

Heatwole, the Pebble Partnership executive and a lifelong Alaskan, echoes that sentiment. “I recognize the need for responsible resource development to create jobs and economies that allow me to live in this land that I love.”

The upcoming year could be a decisive one for Pebble’s future. Beyond the battle in Congress, at the EPA and in the courts, voters in Alaska will consider a ballot measure this fall that could allow state legislators to ban the mine. It’s a war on many fronts, with neither side certain of the outcome.