The company hoping to develop the Pebble mine is casting a broad net in pursuing its legal claim that the EPA worked with anti-mine activists to derail the project, issuing a flurry of subpoenas to dozens of groups and people across the country in a hunt for information dating back a decade.

Many of those fighting the subpoenas in courtrooms from Washington, D.C., to Anchorage say Pebble Ltd. Partnership is trying to silence foes of the copper, gold and molybdenum prospect by raising the specter that they'll have their privacy invaded and be dragged into court.

"It's an attempt to chill the opposition to a really, really bad project" facing nationwide condemnation, said Vicki Clark, executive director of Trustees for Alaska, an environmental law firm that has been served a subpoena and is representing others served, including Tim Troll, a Bristol Bay activist who worked for mine opponent The Nature Conservancy.

The 60-plus subpoenas seek the production of personal emails, documents and other communications with the EPA as well as with other activists and groups. Pebble wants to view discussions about the project, the EPA's efforts and related matters.

The subpoenas have been issued by Pebble Ltd. attorneys as part of the company's case against the EPA. Pebble alleges the EPA created de-facto committees stocked with anti-mine activists to support a pre-planned effort to stop the mine and failed to follow public notice laws associated with the Federal Advisory Committee Act.

The agency has fired back in court to say its communications and meetings with people who disagree with Pebble Ltd. do not constitute federal advisory committees.

Pebble's targets include numerous conservation groups, Native organizations and hunting or fishing associations, including the Bristol Bay Regional Seafood Development Association, a marketing group supported by fishermen and its former director, Bob Waldrop.

In a court filing, Waldrop said he was handed a subpoena in late August and called the event "profoundly impactful and intimidating." Because of it, he said, he will forever think twice about speaking out again on big issues such as the Pebble prospect.

Also on the list is Bristol Bay Native Corp., whose board came out against the mine; the University of Alaska, where some educators and researchers played a role in creating a key EPA report; even jeweler Tiffany & Co., which has promised not to buy any gold from Pebble.

Pebble, owned by Northern Dynasty Minerals of Canada, said it wants to understand the discussions that led up to what it calls the agency's unprecedented attempt to preemptively stop the mine before a final plan was submitted for permits. The EPA's 2014 report, the Bristol Bay Watershed Assessment, found that a large open pit mine of the sort proposed by Pebble would damage the prized Bristol Bay salmon fishery.

Pebble said it's been frustrated by the lack of information provided by the EPA. It alleges the limited documents it has received under the Freedom of Information Act and a congressional oversight hearing last year show that the agency had for years planned a preemptive veto and colluded with mine critics to justify that decision.

"Their public narrative is they took these steps because they received a petition from some Alaska Native tribes in 2010 but clearly there was a lot of stuff happening behind the scenes far in advance of that," said Mike Heatwole, Pebble's vice president of public affairs.

Lawyers opposing the subpoenas said the sheer number of them is unlike anything they've ever seen. They say the far-reaching request for information involves hundreds of people and is an attempt to burden mine opponents and gather strategic internal communications.

"Pebble has thrown a giant boulder into the pond and generated a legal tsunami," said attorney Jeff Feldman, representing the Alaska Conservation Foundation, and Samuel Snyder, a former employee of the group. "The battle to fight the subpoenas has cost a lot of groups a tremendous amount of time and money."

Trout Unlimited has also been served, along with its former Bristol Bay campaign manager, Shoren Brown, who said in a court filing that if he's forced to reveal information it will negatively affect how he communicates about the project in the future. The next time someone wants to seek action from the federal government that could upset wealthy interests, they'll need to ask themselves if they can afford a lawyer, he said.

Heatwole said Pebble Ltd. needs to issue so many subpoenas to know what to ask the 35 EPA officials, activists and others it intends to depose for questioning.

"We absolutely respect the right of people to have their own opinion of a project," he said.

Court filings in Anchorage asking U.S. District Judge H. Russell Holland to quash the subpoenas argue that Pebble Ltd. needs to pursue the information it seeks from the EPA, not people and groups who voiced their displeasure to the agency.

"Just because you had the temerity to exercise your constitutional right to communicate with the government should not put you in the crosshairs of a subpoena," Feldman said.

Much of Pebble's $15 million budget this year is going to fight the EPA. The company's concerns have sparked an inspector general review of the agency's efforts. Also, in response to a Pebble motion, Holland late last year ordered the EPA to halt work on efforts to block development at the mine. Holland recently granted Pebble's request to force testimony from Phil North, a now-retired EPA scientist who, according to Pebble, worked with tribal groups and environmentalists in an effort to stop development.

The deposition for North, who is thought to be living in Australia after retiring in 2013 to sail the globe with his family, has been set for Nov. 12 in Anchorage.

The EPA has been unable to retrieve all of North's emails as well as some documents from a hard drive and encrypted files on a thumb drive.

"We're trying to establish the breadth and depth of what was going on here," Heatwole said. "We've been given a very incomplete picture by EPA and so we have to start somewhere."

The activists subpoenaed by Pebble say that unlike North or other current and former EPA officials, they are not party to the lawsuit and shouldn't be dragged into it.