This photo from HAZ looks like a petroglyph to me:
igallery/image_page.php?id=1214I haven't seen a photo of the "oro" one, anybody got one? I didn't see it on my hike there. I can't find my photos, but they're around in the house somewhere, film ones, though.
Up here in the White Mtns. we have so many odd petroglyphs, some of them are just downright spooky. There are thousands of them around here, within 20 miles of Springerville, and I have given up thinking I have seen all forms of them. Sure, we have the spirals, animals, etc., but also some you can't define.
A couple of things you look for. Modern graffiti usually has a scratched in look. The ancient ones don't look that way. Also, with the hundreds of years since the ancient ones were done, a little desert patina has started to soften and cover them.