@Great Argus Yes I think so. That is the species that is most common in the Tucson area and most often seen by people. It is the only kind I have seen in the wild in southern Arizona.
@Arizona Docent It appears to have a pretty good diamond pattern from what I see, so that's what I guessed! Quite a few species of rattlesnake live in southern Arizona though from what I understand!
@Great Argus Arizona has more species of rattlesnake than any other state. (I forget the exact number, though 13 seems to be in the back of my mind).
@birdsandbats I suppose diamondbacks are relatively easy if you try to go and find them. I have a photographer friend who specializes in reptiles and is an officer in the Tucson Herpetological Society and she finds them often. The key is to go out at dusk, as is the key with a lot of wildlife viewing. I have never gone looking for them myself, but have run across them randomly (always at dusk) on a few occasions (ASDM, Sabino Canyon, Sweetwater Wetlands).
I should clarify that this was on a path that is for staff only and was roped off to visitors. I was standing just behind the rope photographing the sunset. When staff find rattlesnakes on the grounds where visitors walk, they collect them and move them off grounds (though they usually come back I suspect).
@Arizona Docent It has been found that rattlesnakes have home ranges and are quite good at returning to them if moved. My local facility moves Western Rattlesnakes away from paths irregularly throughout the warmer months, and keeps a photographic record of each snake. They found many of the snakes are the same ones from year to year.