A 112 square kilometer research watershed was instrumented to study basic hydrologic processes in the mountainous areas of the Northeastern United States. Within this area the rainfall-runoff relationships are characterized by fast response but relatively low volumes of runoff. There is very little evidence of surface runoff and the partial-area hydrology concept appears to describe the runoff process. A partial area storm runoff process has been described and experimentally verified for an extremely small area in this watershed. This process attributes storm runoff to channel and near channel areas where surface runoff is generated because the groundwater or perched water table has intersected the surface and there is no resulting infiltration. Storm data for nine watersheds have been analyzed and the results demonstrate that the partial area concept can be generalized to large areas. Other data relating to the general hydrology and water balance of this watershed are also described.