The applicability of geophysical methods to experimental watershed research is demonstrated by a study of a 106-acre forested watershed in central Pennsylvania. Data from a shallow seismic refraction study and an electrical resistivity study of the watershed were used to determine the depth of soils, their volumes, depth to bedrock, configuration of the bedrock surface and delineation of the bedrock surface and delineation of the water table. With this information on the subsurface conditions, the hydrologic properties of the watershed were described in greater detail. This information will be of value in explaining the watershed's response to various watershed treatment practices that eventually will be used.