The Chequamegon-Nicolet National Forest (CNNF) in northern Wisconsin contains numerous groundwater-dependent water resources that may be vulnerable to potential effects of land development, mining, and climate change. In order to monitor water quality over time, 138 of the lakes, streams, wetlands, spring ponds, springs, and wells were sampled in 2011-2016 and resampled in 2021-2022.