New Buffalo and the marshes of Lake Pottowottomee at the mouth of the Galien River, Michigan shewing the facilities for constructing a harbor of refuge; from survey made in September 1857 by assistant John R. Mayer, under the direction of Brevet Lieut. Col. J.D. Graham Major, U.S.Top. Engineers. Superintending Engineer of Lake Harbor Works.
The soundings are in feet & tenths of a foot. "The figures on land express the elevations above the lake surface in feet and decimals. The horizontal curves or contour lines are drawn at intervals of 3 feet of perpendicular elevation." "Accompanying Lt. Colonel J.D. Graham's annual report (no. 200) to Chief Top. Engineer, dated Chicago, September 30th 1857." "Map G. No. 54." 1 map; 65 x 101 cm This map is in the public domain. Please attribute access and use of this digitized map to the Stephen S. Clark Library, University of Michigan Library.
Graham, J. D. (James Duncan), 1799-1865.,Mayer, John R.,United States. Army. Corps of Topographical Engineers.