They just look like eroded mountains in the desert to me. The United States is filled with them from the Rocky mountains to the Sierras. From a commercial flight, almost everything in that region looks like this.
I wholeheartedly agree. Worth checking of course, just in case, but look natural — and looking at their estimated size, they could hardly be artificial.
OTOH, there are much larger structures from ancient Egypt; there’s a well-preserved mudbrick temple from early Egypt that has a wall something like 3/4 of a mile long.