New Environmental Protection Agency chief Gina McCarthy is visiting the proposed site for the giant Alaskan copper and gold Pebble mine on Tuesday, as key parties seek to win this fresh influential decision-maker to their side in a fierce ongoing debate.

On one side, mine critics say that a profitable salmon fishing industry and nearby natural resources could be destroyed by mining waste and overdevelopment. Against that argument mine developers claim that thousands of new jobs could be supported by this fresh economic engine.

EPA spokeswoman Marianne Holsman told International Business Times that McCarthy’s Pebble tour comes as part of a broader trip to Alaska highlighting climate change.

McCarthy visits Dilingham, Iliamna, and the mine site on Tuesday. Dilingham and Iliamna are two small towns in the wider Bristol Bay region, which produces a good deal of the world’s sockeye salmon and which could host the potential mine, worth $55 billion in deposits.

“This is a fact-finding mission for the Administrator,” wrote Holsman in an email. “She is looking forward to seeing the area firsthand and hearing directly from community leaders and others with a stake in this issue.”

One party with an obvious key stake in the debate is the partnership behind the mine, led by the British Anglo American PLC (LON:AAL) and the Canadian Northern Dynasty Minerals Ltd. (TSE:NDM).

Pebble Partnership CEO John Shively told IBTimes that McCarthy’s visit is a welcome change to the policies of her predecessor, former EPA administrator Lisa Jackson, who he claims took a less favorable view of the mine project.

“Lisa Jackson never visited the project [site],” said Shively, who acknowledged that Jackson did meet with developers at least once, in 2010.

“When Alaskan natives who were open-minded about the project wanted to meet with her, she turned them down on several occasions,” he continued, “even though she met with the opposition."

“The fact that she would not meet with Alaskan natives who were open-minded about the project said a lot about what she was thinking,” said Shively.

Shively wants McCarthy to take away a solid sense of the natural space around the proposed mine, which he says project critics have misrepresented.

He also hopes that McCarthy will not veto the project under the Clean Water Act’s Section 404c, which allows the EPA to block developments which damage wetlands or nearby water resources.

Yet that veto, described by some as pre-emptive and unprecedented, is exactly what mine critics are seeking.

Geoffrey Parker is an Anchorage attorney who helped native Alaskan tribes file a petition to the EPA for such a veto, in 2010. On her visit, McCarthy should realize and see directly that there are several metal deposits in the region, which together justify advance EPA planning, said Parker.

“There is no reason to wait for applications for permits to develop any particular deposit,” he told IBTimes. “This situation requires advance wetland planning, and therefore an advance determination of restrictions and prohibitions.”

Backers of a veto point out similar vetoes have been deployed about a dozen times in the past few decades.Joel Reynolds, an attorney with the Natural Resources Defense Council in New York, has said that an April 2013 decision in Washington D.C. courts showed that the EPA can still veto a project, even after permits have been approved.

Still, it’s unlikely that McCarthy’s visit will result in immediate and tangible concrete policy.

The next step, cited by both sides as important, is the finalization of a draft environmental study on the mine’s impacts, expected before the end of 2014.

“We’re hoping that they will finalize the watershed assessment immediately, and move into 404c authority,” said Kimberly Williams, a spokeswoman for tribal association Nunamta Aulukestai, which represents ten villages and tribal governments in Bristol Bay.

Emphasizing the Clean Water Act will raise the environmental bar that developers must meet, to protect crucial streams and their salmon, said Williams, regardless of whether a veto is ultimately issued.

Luki Alkekok, who chairs Nunamta, said meetings with McCarthy on Tuesday were all-attended and productive. In a remark that could dampen hopes for developers like Shively, he described the meeting as similar to previous visits by former EPA chief Lisa Jackson.