Mine Tailings (IMAGE) University of Arizona College of Engineering Caption The front of the mine tailings pile at the Iron King Mine and Humboldt Smelter Superfund Site in Yavapai County Credit University of Arizona Superfund Research Center Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.