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Dysart Woods, an outdoor lab of Ohio University, is a 23-hectare old-growth forest in southeastern Ohio that has not been cut. The mineral rights underneath Dysart Woods are held by the Ohio Valley Coal Company (OVCC), which is conducting longwall mining room-and-pillar mining under the old-growth forest area, and longwall mining outside the buffer zone proposed by OVCC under the permit issued in 2001. This buffer zone has been defined using the angle of influence method, which is mainly used to protect from subsidence. However, it is not enough to protect the hydrogeologic properties of groundwater flow system. The purpose of this study is to understand and evaluate the impacts of subsurface mining at Dysart Woods on the upper most aquifers using a qualitative and quantitative approach. Time series analysis was applied to precipitation, hydraulic heads, barometric pressure, and Earth tides to compare the changes of pre-mining and post-mining conditions. Results of transient data analysis reveal higher permeability and hydraulic conductivity after mining, and a decrease in the storage capacity of the underground water flow system. Earth tide analysis also suggests that groundwater flow regime responds better to earth tides before mining than after mining conditions, which is probably due to the fractures of rocks and drainage in the system caused by mining activities. Estimation of hydrogeologic parameters indicate that the capacity of aquifers to hold water against gravity has decreased, which is probably caused by more fractures and drainage due to mining activities. The results suggest that in order to preserve the ecosystems that are relying on the groundwater flow system, more strict rules and regulations should be made. Combination of time series analysis and flow modeling may provide more useful information about the current and future hydrogeology of a region.