The U.S. Army Corps of Engineers this week warned that the proposed Pebble project — a vast gold and copper mine near the headwaters of Alaska’s Bristol Bay — was impossible to build without causing significant damage to the region’s pristine waters and salmon fishery.

The Corps stopped short of halting the mine but found the developer, the Pebble Limited Partnership, was unlikely to meet the level of mitigation that would be required under the Clean Water Act to offset the impact on wetlands.

The Trump administration has now done what the previous administration would not — it gave the proposed Pebble project full consideration under the National Environmental Policy Act (NEPA). While the previous administration pre-judged the project with an unprecedented preemptive veto, the Trump U.S. Army Corps of Engineers and all cooperating agencies have given it a full review.