That looks like that could be a Chihuahuan Raven (Corvus cryptoleucus); as the ranges of the two Corvids overlap in that area and the tail looks a little less wedge-shaped than that of the Common. Without a size reference or looking at the head, i'm only guessing.
I don't think this is a Chihuahuan. The ravens in Petrified are pretty big birds and I may be too far north in Arizona to see them. I may have been in their range while in New Mexico (along with seeing one at a wildlife rescue center). I don't think I'd trust myself with the white vs. gray base feathers. I have a few pictures of what I know are common ravens (Yellowstone) that look to have pretty white base feathers.
Thanks for taking time to explain! I've only been to Arizona twice and you have much more experience with Corvids of that area. I had a tough time telling the two apart unless they were very close (for size reference) and could hear them and sometimes even then I couldn't be sure. Voice is tough for me - I'm originally from Anchorage, Alaska and I swear that the Commons up there are slightly larger and have deeper voices than the ones I have encountered in both NW Washington and in Arizona.
You're very welcome! It took a while for me to get used to telling ravens and crows apart when I first moved to an area where I see the two birds on a daily basis (I'm originally from Portland and ravens are fairly rare there). I think ravens may also have regional accents to their calls too (I think there's a paper on that somewhere but I can't remember what their findings were). And I think the further north you go animals generally get larger, so the ravens up in Alaska are pretty big compared to ones in the Southwest. The ravens here in Montana are pretty big too.
Thanks! They're one of my favorite birds to photograph.
The ravens in the National Parks are pretty friendly. They'll hang around (maybe because they've been given food before) and be all adorable while people are visiting. If they figure that you're not going to give them food, they'll take off in search of a gullible tourist They are super awesome birds to hang out with.