"Topography by photogrammetric methods from aerial photographs taken 1950. Field checked 1951."
"The Geometronics Service Center has regenerated all map information, with the exception of contours, utilizing digital procedures. Modifications to USGS map base made using 1988 aerial photography and 1992 correction guides furnished by the Eastern Region."
10,000-foot grid based on Michigan coordinate system, north zone; 1000-meter Universal Transverse Mercator grid, zone 16.