19th century US plat map iconography

[Falconius]

Ah, awesome. Makes a lot of sense now. Thanks for telling us.

[KMAlexander]

Some examples, just because I find this stuff really interesting...

Here's it more hatching, less defined.

Sand and Gravel puts are more pit-like here, (Four down, three across.):



Also these:



This was REALLY common and was a big reason why I was looking elsewhere. For a long time, I wondered if it wasn't some sort of hydrological symbol, like a french well, or something.



Shoulda done what Rwhyte did and went to the source. Excellent work.