I think this may be a remnant from colonisation, probably French, possibly Portuguese. It resembles Portuguese triangle forts elsewhere.
What is odd:
There is a similar style fort here (nearby).
These are more than likely irrigation works. The native people of the Americas were incredible agriculturalists, they even bioengineered the Amazon rainforest (I.e they created it). Unfortunately around 90% of them were killed in the 100 years post contact through plague/illness.
This is an incredible book if you’re interested in the subject.
Good idea to report the issue. I did this with Google Maps on Chrome a couple days ago. I will post an egroup with your idea about getting friends to report the issue.
I've also called AZ DOT, but no one I spoke with knows how to contact Google. I wonder if the state DOT have ways of reporting closures to Google ? If so you would think they could also report open roads ...
Bing is working fine here: