My first post was pretty much "off the cuff", and I didn't put a lot of time into researching what your placemarks could be. No offense intended. I was trying to put an "Occam's Razor" point of view, i.e. a simple explanation, to what I perceived as a collection of "Chariots of the Gods" alien/UFO symbols. The number of people who post such things in Google Earth seems to be growing, with fantastic and fanciful claims about Atlantis, UFO's, and Bigfoot. After reading your reply, I can see that isn't what your collection is about.

I'll admit that after having looked a little more closely, and browsed around, and done a little research, many/most/all of your placemarks may be exactly as Mr. Payne indicates. No doubt there is something interesting going on with this collection of placemarks. And having browsed around several oilfields, you're right, there are many unusual, even oddball marks on the ground, but none quite as structured, consistent, and repetitive as the ones you've shared with us.

After a little reflection, here's what I can add to the discussion:

First, most of the objects are all of approximately the same scale. 300 feet, plus or minus about 50 feet, seems to be the size or scale of the multiple circles, the 4 and 6 line marks, the hexagonal marks, the star shapes, and the glyphs.

Second, they are typically linearly arranged in groups of the same type of pattern, and the spacing is consistently approximately 0.25 miles or so around the state.

Third, there are a few placemarks which do not fit the pattern, i.e. the "zigzag lines" placemark near the center of the group.

Age is still hard to determine from satellite imagery, but in comparing the 1993 imagery in Google Earth with the current imagery, there's not much change at all. That just indicates the rate of change is slow, it doesn't say much about when they were created. It is possible they were created relatively recently, but I have no way of knowing or verifying that. It's also possible they're pretty old, given the slow rate of change. I'd surely defer to anybody with local connections, who is informed about this subject, because I'm surely not.

Interesting collection. Thank you.