In some areas, original land surveys or other documents indicate that the Land Unit lines shown on USGS topographic maps are incorrectly placed, or that the designated Land Unit Numbers are incorrect. In such cases, the corrected lines are used by the Subsurface Section of the Indiana Geological Survey (IGS) to describe well locations and to file documents for wells. Location descriptions contained in the PDMS have been redescribed to reflect these corrections.
Probably need to revisit this topic in light of IGS "errors" in describing wells in Knox Co.