Aerial view of tundra at Alaska's Bristol Bay.
Bristol Bay Watershed Under an overcast sky, an aerial view of the rugged Bristol Bay watershed in the area of the proposed Pebble Mine development in southwest Alaska. The Pebble Mine project is a large and controversial copper, gold, and molybdenum open pit mine proposed for develop within the watersheds draining into Bristol Bay. The Bristol Bay watershed lies within the region of Southwest Alaska, near Lake Iliamna and Lake Clark. An impact study is being conducted and supported by environmental groups, including the Nature Conservancy, to focus attention on the value of this fragile ecosystem and vital salmon spawning habitat. © Bridget Besaw


The Nature Conservancy Applauds Pebble Mine Announcement

Army Corps of Engineers finds mine will significantly degrade Bristol Bay’s environment.

The following is a statement by Steve Cohn, Alaska state director for The Nature Conservancy, after the Army Corps of Engineers found the proposed Pebble Mine in Alaska “cannot be permitted” as proposed under the Clean Water Act following a determination that discharges at the mine site would cause unavoidable, adverse impacts and significant degradation of aquatic resources in Bristol Bay:

“We commend the administration and the Army Corps of Engineers for adhering to scientific standards in its determination. It is evident now, more than ever, that the headwaters of Bristol Bay – home of the planet’s most productive rivers for wild salmon – cannot also accommodate the environmental damage caused by the proposed Pebble Mine. 

“Our long-stated concerns with Pebble Mine extend far beyond the direct loss of wetlands, open waters and streams, which would be unprecedented for an approved Clean Water Act permit. Pebble Mine is encumbered with further significant risks, including but not limited to a flawed dam design, lack of catastrophic dam failure analysis and a need for unproven technologies to treat toxic wastewater management in perpetuity within a flood-prone, seismically active watershed.

“The compensatory mitigation plan called for today by the Corps is not only likely infeasible but will not abate the mine’s threat to this globally significant salmon fishery. A Clean Water Act permit should not be authorized for Pebble Mine. Today’s announcement acknowledges that Bristol Bay’s future must align with the health and well-being of Alaska Natives who have cared for and relied upon these lands and waters for millennia.”

The Nature Conservancy is a global conservation organization dedicated to conserving the lands and waters on which all life depends. Guided by science, we create innovative, on-the-ground solutions to our world's toughest challenges so that nature and people can thrive together. We are tackling climate change, conserving lands, waters and oceans at an unprecedented scale, providing food and water sustainably and helping make cities more sustainable. Working in 76 countries and territories: 37 by direct conservation impact and 39 through partners, we use a collaborative approach that engages local communities, governments, the private sector, and other partners. To learn more, visit or follow @nature_press on Twitter.