The lawsuit filed Monday by the Chilkat Indian village of Klukwan calls for revocation of the permits granted to Constantine Metal Resources Ltd. upstream of the Chilkat River near the port of Haines in southeast Alaska.
Tlingit Indians thrived because of the abundance of salmon in the watershed, Klukwan tribal president Kimberly Strong said in a statement.
"Hardrock mining is a threat to our Chilkat wild stock salmon and the sustainability of our community," she said.
The lawsuit contends the federal Bureau of Land Management issued permits after considering the effects of exploration but not of a mine.
Kenta Tsuda, an attorney for environmental law firm Earthjustice, said the interaction of federal mining, environmental and land policy laws allows mining companies that establish a commercially valuable deposit to be vested with certain property rights to develop their find.
"That change would constrain BLM's ability to protect those lands," he said.
BLM spokeswoman Lesli Ellis-Wouters said the agency could not comment on pending litigation.
Liz Cornejo, Constantine's vice president for community and external affairs, said the company is reviewing the lawsuit but she had no immediate additional comment.
Vancouver, British Columbia-based Constantine Metal Resources Ltd., was formed in 2006 to explore for copper, zinc, gold and silver in what it's calling the Palmer Project about 35 miles (56 kilometers) northwest of Haines, a fishing and tourism community.
Japan's Dowa Metals & Mining Co. in 2013 agreed to invest $22 million over four years in exchange for a 49 percent interest in the project. Company officials last year said a decision on developing a mine, or its design, was years off.
Critics fear tailings ponds that could breech and send acid-mine drainage or other mine pollution into downstream waters.
The exploration is near creeks and a river that drains into the Chilkat River, home to five species of salmon, steelhead and trout. The surrounding area is habitat for mountain goats, moose and grizzly bears and is best known for an early winter gathering of bald eagles.
Long after other rivers freeze, the Chilkat remains open and up to 4,000 eagles descend to feed on carcasses of salmon that enter the river to spawn and die. The state created the Alaska Chilkat Bald Eagle Preserve to protect salmon and the world's largest concentration of bald eagles on 75 square miles (194.25 sq. kilometers) along the Chilkat and tributaries.
Meredith Trainor, director of the Southeast Alaska Conservation Council, said the BLM, by issuing permits piecemeal, is ignoring its responsibility to conduct a thorough assessment.
"What we're asking the BLM to do is to do a more comprehensive analysis of the potential impacts of that first-level approval, the exploration level, so that they've taken a look at the entire mine project before they start to go down the road of allowing exploration," she said.
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