Relief shown by contours and spot heights. From: Geological survey of New Jersey : maps. [Trenton, N.J. : State Geologist, 1868]. Iron mines shown in red. "Note. The curved lines denote the contours of the hills, formed by horizontal planes at the distance of 20 feet apart. The numbers upon the summits of the hills denote their height in feet." "Lith. Julius Bien ... New York."
