 From 1880-1980 the Coeur d'Alene basin was one of the most productive silver, lead, and zinc mining regions in the country.The waste from the mining, estimated at 72 million tons, contaminated land and downstream waters, including the Coeur d'Alene River and Lake Coeur d'Alene.As of 2012, the Silver Valley was the second largest Superfund cleanup site in the nation, as designated by the United States Environmental Protection Agency (EPA).