President Donald Trump on Thursday pulled the U.S. out of an agreement with Washington, Oregon and four American Indian tribes to work together to restore salmon populations and boost tribal clean energy development in the Pacific Northwest, deriding the plan as “radical environmentalism” that could have resulted in the breaching of four controversial dams on the Snake River.

The deal, known as the Resilient Columbia Basin Agreement, was reached in late 2023 and heralded by the Biden administration, tribes and conservationists as historic. It allowed for a pause in decades of litigation over the harm the federal government’s operation of dams in the Northwest has done to the fish.

Under it, the federal government said it planned to spend more than $1 billion over a decade to help recover depleted salmon runs. The government also said that it would build enough new clean energy projects in the Pacific Northwest to replace the hydropower generated by the Lower Snake River dams — the Ice Harbor, Little Goose, Lower Monumental and Lower Granite — should Congress ever agree to remove them.