Examine the effects of dams on salmon and the wider Elwha River ecosystem in Washington State and explore evidence of their recovery four years after the biggest dam removal project in history, in this video produced by The Nature Conservancy and GBH featuring video from H₂O: The Molecule That Made Us. Use this resource to learn about the damaging effects that human activities can have on animal habitat and the impact that ecosystem restoration efforts can have on populations of living things.