We all rely on base metals. Cars, computers, and other common electrical devices at our disposal require copper. What's more, says Mike Heatwole, vice president of public affairs for the Pebble Partnership, "copper is one of the building blocks of the green economy." Wind turbines, for example, can use thousands of pounds apiece. Heatwole, two of his co-workers, and I have arrived by helicopter at a bare hill overlooking the site of the proposed mine. Buried beneath the ground here are an estimated 40 million tons of copper, 107 million ounces of gold, and 2.8 million tons of molybdenum (used as a hardener in lightweight alloy products like surgical instruments). The value of this mother lode ranges between $100 billion and $500 billion. But unlike the value of the salmon fishery year in and year out—upwards of $120 million—once these geologic riches are gone, they will never come back.

The deposit is divided into two sections—a western district, where the ore could be extracted by open-pit mining, and an eastern district, where the ore is deeper and would require an underground operation. Particulars will not be revealed until 2012, when the partnership submits its official plan to state regulatory agencies to start the permitting process, but the general outline, based largely on documents Northern Dynasty released several years ago, may look like this: Besides two large mines, the complex likely would include a mill to crush and separate metals; immense damlike impoundments to contain the fine-grained waste, or tailings, from the mill; a slurry pipe to transport the milled ore to Cook Inlet; a deepwater port on Cook Inlet; a haul road along the same corridor; and 250 to 300 megawatts of power, generated either on-site or outside the region.

"The only place worse to put a mine would be my living room." That's what former Alaska governor Jay Hammond said of Pebble, according to his widow, Bella. Considering that their living room is yards away from wild and remote Lake Clark, across from the glacierbound peaks of the Chigmit Mountains, Hammond couldn't have issued a stronger indictment. Of the many threats posed by the mine—disruption of spawning grounds along the haul road (which would cross scores of streams), draining of spawning grounds (including Upper Talarik Creek) near the mine, the outright destruction of spawning grounds within the mining complex—what concerns people most is acid mine drainage. When a sulfur-bearing ore such as the Pebble deposit is exposed to air and water, it produces sulfuric acid, which accelerates the dissolution of copper and other minerals. The resultant metal-laden, acidic cocktail can kill fish and other organisms.