"Compiled in 1955 by photogrammetric methods and from USLS Charts 76, 1953; 7,73, and 77 1954; 74, 1955. Horizontal and vertical control by USGS, GSC&GS and CE. Photography field annotated 1954."
Depth shown by isolines.
"10,000-foot grids based on Michigan coordinate system, central zone Wisconsin coordinate system, south zone."
"1954 magnetic declination for this sheet varies from 1°30' easterly for the center of the west edge to 0°45' westerly for the center of the east edge. MEan annual change is 0°01' westerly."