A Carex aguatilis daninated fen in the Peru Creek drainage, Colorado Rocky Mountains has been impacted by drainage from the Pennsylvania Mine. Metal concentrations in leaves, roots and standing dead leaves were analyzed and it was determined that Zn, Cu, and Al were probably the leading cause of poor plant health. Published in Wetland and Riparian Ecosystems of the American West: Proceedings of the Eight Annual Meeting of the Society of Wetland Scientists, on pages 26 - 29, in 1987.