1. Geohydrology of the valley-fill aquifer in the Ramapo and Mahwah area, Rockland County, New York Yale Public content 1982. 2002-06-01T04:00:00Z. 2023-03-14T19:31:23Z. Geological Survey (U.S.). The Survey. English. cartographic image. Public. New York (State), Rockland County, and Rockland County (N.Y.).