Here's an example: https://mappingsupport.com/p/gmap4.php?ll=38.025076,-119.421796&z=15&t=t4&markers=||38.018311,-119.419928^^<span%20style='font-weight:bold;font-size:1.2em;'>38.018311,-119.419928</span>

At first I thought it was some sort of benchmark - but seeing where they are located (apparently at random in the physical world) it appears that they may be some type of alignment marks for the mapping/map-making process. Google was not my friend with this one. Any ideas?

It's a "principal point". The letter are probably just an identification code: http://pubs.usgs.gov/gip/TopographicMapSymbols/topomapsymbols.pdf

You might get more info by asking: https://answers.usgs.gov:443/cgi-bin/gsanswers?tmplt=4



Edited 1 time(s). Last edit at 08/05/2016 12:02PM by eeek.

And, from here:

Principal Point - The principal point is the point where the perpendicular projected through the center of the lens intersects the photo image.

So, in short, there's nothing on the ground or anything special about these points, and thus no need for anyone to drag anyone else through random shrubbery to try to find something there...



Edited 1 time(s). Last edit at 08/05/2016 12:42PM by basilbop.

OK then.

Was there another very-deeply-hidden message somewhere... ? :-)