Somewhere in the "Great Southwest"

I only know three things about these photos.
1.) They are from somewhere in the "Great Southwest."
2.) The only words accompanying them were: "G7. Precarious boulder-top perches."
3.) If they were found in the Northeast, a certain SHPO would call them examples of "the disposal of field clearing stones stacked on bedrock outcrops by 18th century hilltop farmers to maximize the amount of plowable land in the nearby fields."