United States. Geological Survey. U.S.G.S. Alternate title: Sheffield, Nass. - Conn. - N.Y. Polyconic projection. Relief shown by 20 feet contour interval and spot heights. Surveyed in 1884-5 in cooperation with the states of Mass. Conn. And N.Y. Triangulation by S. Borden and H. F. Walling. Verso: The topographic maps of the United States.