Associated Press

ANCHORAGE — A federal agency announced a preferred transportation route for precious metals leaving a proposed mine, angering opposition groups who say the decision represents a significant change that needs public review.

The U.S. Army Corps of Engineers made a preliminary determination that a “northern route” is the practical and least environmentally damaging option for the Pebble Mine, The Anchorage Daily News reported Saturday.

The open-pit mine would be about 200 miles southwest of Anchorage, straddling salmon-producing headwaters of the Bristol Bay fishery.

A northern route carrying copper and gold concentrate would travel over land about 80 miles around the coast of Lake Iliamna.

The Corps is expected to release a final environmental review of the project, possibly next month, before determining whether it issues a permit, a permit with conditions or denies Pebble’s application, Corps spokesman John Budnik said.

The Corps’ preliminary preferred alternative is different from the original option submitted by project owner Pebble Limited Partnership.

Pebble submitted plans in late 2017 calling for a southern route with an ice-breaking ferry across Lake Iliamna.

The northern route includes a pipeline for the metals and “dramatically reduces truck traffic,” Pebble spokesman Mike Heatwole said Friday.

“This is about Pebble pushing for a bigger mine under the guise of the smaller plan,” said Rachel James of conservation group SalmonState. “This is a con game, a giant bait and switch, and the Army Corps is in on the scam: analyze for one option and allow for another.”

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The Bristol Bay Native Corp. said in a statement that the northern route could support a larger mine, which the organization views as an indication Pebble will seek extensions beyond the 20-year permit being pursued.

The regional Alaska Native corporation has said it will not make its lands available for the route.

“It is unacceptable for (Pebble) to make such a significant change in its plans after the completion of the preliminary final environmental impact statement,” said Dan Cheyette, the corporation’s vice president of lands.

“(The northern route) has not been vetted and scrutinized by both the public and cooperating agencies on the same level as other transportation routes,” he said in a statement.

Alannah Hurley of United Tribes of Bristol Bay said, “The decision is another attempt to streamline and do things behind closed doors, so the public can’t engage.”

• This is an Associated Press report.