ABSTRACTMining operations within the Coeur d'Alene District of northern Idaho have been continuous for over 85 years. Data presented herein demonstrate that early day mining and milling wastes are now affecting the ground‐water quality in several locations. One of the affected areas is the lower Canyon Creek Basin located in the Coeur d'Alene District near Wallace, Idaho.Ground‐water pollution of the Canyon Creek Basin results from leaching of old mine tailings that are intermixed with the upper part of the sand and gravel aquifer. High zinc, lead and cadmium concentrations occur in ground water and soil samples taken from the portion of the sand and gravel aquifer containing old mine tailings.Analysis of water samples from a settling pond located in the upper portion of the study area indicates that the pond water is not the source of the heavy metal concentrations found in the ground water. However, the water from the pond's decanting system provides recharge to ground water and compounds the prob