Probably both Black Vultures and Turkey Vultures. Yes, vultures occur throughout the southwestern United States. A Golden Eagle would also be large, but not black.

OK , I'm pretty sure there isn't but when I was 9 , my brothers , my cousin and me were walking a path thingy canal that was really far. It actually looked like a swamp mixed with a desert because there was red sand and rocks where we were walking but water and a lot of aquatic plants.we found this path because it was behind our uncles condos and we orobally walked a few miles. Well we walked and walked and their was these gas pipes coming from this gas building we looked over and by the ground was a huge , black bird. I liiteraly saw all black. Black feet , feathers , beak.He was on the other side of the canal /swap thingy so I couldn't see his or her eyes etc. We were all amazed because the bird was freaking huge. Bigger than an me at wingspan.I'm pretty sure. None of us had phones so we couldn't take a picture and if you have seen a canal they have huge holes on the side and I swear on everything , the bird saw us and went into the hole. I've never went back there and I've been keeping this a secret because I'm pretty sure people wouldn't believe me or my family.I know some of these things might sound false. Big black bird in a desert ..? That's what I saw and I do remember where the condos are but I'm 15 now so I don't know if the canal is still there. Please give me input if a animal like that can actually exist. Thank you and if anyone thinks im lying in my heart I know what I sawv