In a sign of the growing political importance of the fight over whether to permit Alaska's Pebble Mine,Environmental Protection Agency administrator Gina McCarthy said in an interview she may make a personal visit to see where the controversial project would operate.

Six tribes have joined forces with environmentalists and fishing operators have been lobbying the Obama administration to block to proposed mining operation in the Bristol Bay watershed, a remote area that is home to nearly half of the world’s sockeye salmon. The tribes have asked the EPA to invoke its powers under the Clean Water Act to block the mine on the grounds that it would harm the region’s waterways, fish and wildlife, while two companies building the mine, Anglo American and Northern Dynasty, have launched their own campaign aimed at keep the agency out of the decision.

"I would like to take a little bit of a trip out there and see it," said McCarthy, in an interview before delivering her first speech as administrator Tuesday at Harvard Law School.

McCarthy, who met or spoke with 71 senators before being confirmed earlier this month, said she "sensed there was a real interest in this issue" in her discussions with senators from the Pacific Northwest as well as Alaska.

Five Democratic senators from Washington, Oregon and California sent President Obama a letter in early June asking him to consider blocking the mine. Led by Maria Cantwell (Wash.), the senators argued that their states could suffer economically if a huge gold-and-copper mine moves forward.

EPA is still finalizing an environmental assessment of any mine's potential impact on the region, after which it could make a decision on whether to block the companies' permit. Sen. Lisa Murkowski (R-Alaska) has warned EPA against issuing a "preemptive veto" of the project, but she has also urged the Pebble Mine Partnership to formally apply for a permit, which they have yet to do. Sen. Mark Begich (D-Alaska), who is facing reelection, has said he wants to wait until the scientific process is complete before taking a position on the matter.

"Any act that EPA would take would be carefully considered," McCarthy said. "There are significant natural resources in that area, along with significant economic resources. We’ve got to get that balance right."

Both sides have enlisted the help of advocacy groups and consultants to make their case in Washington. Mine opponents, which include environmental groups such as Trout Unlimited, have hired former Obama aides Tommy Vietor, Jon Favreau and Paul Tewes to orchestrate a pubic relations campaign, while the mining companies have hired the Livingston Group and gotten support from the Competitive Enterprise Institute.