Marsh v. Oregon Natural Resources Council
United States Supreme Court
490 U.S. 360 (1989)
Environmental groups (defendant) sued John Marsh, the Secretary of the Army overseeing the Army Corps of Engineers (plaintiff on appeal), to enjoin construction of the Elk Creek Dam, the final dam in a three-dam Oregon river project for which the Corps had prepared an environmental impact statement in 1971 and a supplemental statement in 1980. The Corps proceeded with construction in 1982 despite two later memoranda from state and federal wildlife agencies suggesting greater environmental harm than previously understood, and the environmental groups argued the Corps was required to prepare a second supplemental impact statement addressing that new information. The district court disagreed, but the court of appeals reversed, and the Supreme Court granted certiorari.
Whether, under the National Environmental Policy Act, a federal agency must prepare a supplemental Environmental Impact Statement when new, significant circumstances or information relevant to the environmental concerns bearing on a proposed major federal action come to light.