Graham, J. D. (James Duncan), 1799-1865Mayer, J. R. (John R.)United States. Army. Corps of Topographical EngineersThe 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 cmJPEGac19ac90-110e-4c3a-a5e9-7f7015ea68e0engPublicNew 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.MapsMichigan--Galien RiverMichigan1857University of Michigan