Have you tried to draw a line (or lines) between them and check for pattern(s), from above? hmm, interesting.....
Is that a tree stand in your last pict.? if it is ...you got the "high ground"
AAAAAha, ...I have a theory about this, but i need a little time to put it together, in an easy reading kind of way. I'll get it done by tomorrow, in hope that I'll get over some personal impediments happening today. (just a theory, subject to verification in the field.......as usual)
I've seen this pattern carved on the side of a bluff. A rectangle with a triangle on top of it and a straight line going from the top of the triangle to the point above it. Probably just a coincidence, but do you know the measurements of your pattern? Also, is there a cemetery to the east, within several miles?