Though largely pristine and protected, areas along the Madre de Dios have recently seen the dramatic spread of small mining operations, where miners sift through river sands to extract gold. These activities often use mercury, raising red flags about potential environmental and health effects that are now the attention of several other research efforts. We have been interested in what other long term legacies may be left from these mining activities. USC undergraduate student Renee Wang has been measuring trace metal concentrations in soils and vegetation developed on riverbank sequences of vegetation succession, comparing sites disturbed by mining with those not disturbed. Her preliminary results are intriguing, because they show enhanced metal mobilization from soils at mine-disturbed sites, and corresponding accumulation in the vegetation. Work to understand the mechanisms and potential consequences is ongoing.