Earth Day #40 and the place is Seattleâ€™s hidden river, the Duwamish. Salmon used to run a mile deep in acres of tidal marshes here. Things have changed since that time, the river’s been tamed and contaminated by industry. But determined environmentalists are working to turn the tide. 15 acres of habitat at 13 sites have been restored. The EPA is pushing industry and municipalities to clean up the site – soon. Martha Baskin brings us to the river where kayakers and others are taking things into their own hands.