On Thursday, the Biden administration announced its support for preparing to breach the four Lower Snake River Dams in the Columbia River Basin through an agreement with four tribal nations, two states and several conservation groups. The U.S. Army Corps of Engineers finished building the dams in the 1970s to bolster the Pacific Northwest’s hydropower and agriculture, and they have since become a primary cause of Snake River salmon declines. As a result, multiple salmon runs are veering toward extinction, and the dams have been the subject of litigation for nearly 30 years. … Several other major dams in the Western U.S. have been demolished in the last decade. In 2014, the final dam on the Elwha River in Washington came down, and this year the largest dam removal in U.S. history, on the Klamath River in California, began with the first of four planned removals.