@Arizona Docent considering the likely locality of capture, the Mule deer subspecies here would be ssp. eremicus whose common name is Desert mule deer.
ssp. Crooki whose common name has been assigned Arizona mule deer is not a valid name and if I remember correctly the holotype specimem was an Odocoileus hemionus X Odocoileus virginianus, if you are interested here is a paper written by James R. Heffelfinger from the Arizona Department of Fish and Game on the validity of ssp. crooki http://www.deernut.com/Documents/Status_of_Ohcrooki.pdf
You really are an ungulate nerd! Yes the two mule deer (one of which is pictured) arrived last year as fawns. They were orphaned somewhere in Arizona, not sure where. Before that this exhibit held Coue's white tail exclusively (at least since I moved here in the late 1990's).
@Arizona Docent haha thanks! I am an ungulate nerd and proud of it! Wearn’t there exclusively Mule deer (Odocoileus hemionus) in this enclosure prior to there being Coue’s white tailed deer (Odocoileus virginianus couesi) or was that a different enclosure?
@UngulateNerd92 Actually the exhibit has held exclusively Coue's white tail for decades. It is only one year ago that they got the mule deer fawns and added them to the exhibit. In fact the sign is the old one for Coue's and there is no sign indicating that mule deer are there as well. When they built the desert loop trail with coyote and javelina (how long - maybe 15 years?) there was a sign across from coyote saying future mule deer exhibit. But after a year or two that sign went away and nothing was ever built in that area.
@Ituri yes you are correct there, I cannot believe I didn't even think of that! To my knowledge that would be further north... I will say that the Mule deer I saw while driving through the Gila National Forest (Grant County, New Mexico) last year, did belong to the nominate.
Ah yes, now that would definitely make sense! So in that case, the Mule deer (Odocoileus hemionus) I saw in Grand Canyon National Park did belong to the nominate.