United States. Geological Survey. U.S.G.S. Alternate title: Ramapo, N.Y.-N.J. Polyconic projection. Relief shown by 20 feet contour interval. Surveyed in 1882-88. Surveyed in cooperation with the States of New York and New Jersey. Culture revised in 1909 by C. C. Gardner. Triangualtion by U.S. Coast and Geodetic Survey. Verso: The topographic maps of the United States.