It should be easy to identify those that are due to curvature, though. My understanding is that states parceled according to the PLSS have fairly consistent tow

It should be easy to identify those that are due to curvature, though. My understanding is that states parceled according to the PLSS have fairly consistent township and section divisions, made using a system that takes the earth's curvature into account in a systematic way. This method introduces "corrections" like those in the article at regular, predictable intervals. This is described in the second and third paragraphs of "Survey Design" here: https://en.wikipedia.org/wiki/Public_Land_Survey_System#Survey_design https://en.wikipedia.org/wiki/Public_Land_Survey_System#Surv...