We in Washington have been hearing plenty about the Elwha dam removal. While ecological effects of such a giant project will take years to assess, the removal itself might be a hallmark of shifting perceptions about the costs and benefits of damming rivers. This shift might have begun around 1978 with Tennessee Valley Authority v. Hill, a 1978 ruling in which the Supreme Court ruled that a project to build the Tellico Dam on the Little Tennessee River had to be halted because it would likely lead to the extinction of the snail darter.