I've been wondering this a long time, and just thought I'd throw it out there.
I'll start with Mule deer. Of course, the North part of AZ, along the strip is the home of giant bucks. The Navajo Nation on the N/ NE portions of Az, the Jicarila in NW NM, Southern Utah, SW Colorado, extreme Southern AZ and into Mexico are all destinations for monster mule deer. Even unit 27 in AZ, at one time was loaded with big mulies, and huge numbers of deer. I remember one of my first hunts in AZ ever, I went to Alma NM, then back into AZ, and there were deer everywhere, and some really nice bucks. I had no glass, and no idea what I was doing but I still saw huge mule deer and had opportunities at some bucks I would love to see again, with a little more knowledge to go on.
Maybe it's just me, but it seems like whenever I travel to Southern Utah, SW Colorado, West New Mexico, even NE AZ, there are tons of mule deer, and great genetics, that spread down into Mexico, but the central portions of AZ seem to have low-to-medium density, and modest trophy quality. It seems like much of AZ is almost a void compared to all of the areas around us. Same habitat, same feed from what I can tell, just lower numbers and smaller bucks.
And to Antelope/Pronghorn. Yeah, we've got some, and sometimes a monster shows up, but the same kind of country you see in central/eastern AZ that is rolling hills and grasslands that has some decent herds of antelope pale in comparison to what you seen in the exact same country in neighboring states. It seems every time time drive to NM or CO, I know I've crossed the border when I start seeing antelope everywhere. It's the same country - but something is clearly different.
Anyone else notice the same thing?