JUNEAU, Alaska — The U.S. Army Corps of Engineers plans an environmental review of a proposed gold and copper mine near a major salmon fishery in Alaska.

The Pebble Limited Partnership filed a permit application with the corps last month.

Project details, released Friday, include an open pit mine, tailings storage facility and other infrastructure. Pebble envisions a mining rate of up to 90 million tons a year and says the project could be built in four years, once necessary permits are secured.

Pebble says the project is “substantially smaller” than prior versions and includes environmental safeguards.

But critics say the proposal released Friday reinforces the concerns they have about how the impact of the project on the Bristol Bay region.