When I wanted to get a decent mule deer for the wall, I spend quite a bit of time looking around on where to go and decided on Eastern Montana out of Broadus. I hunted in November when the mule deer where in the rut, and they where everywhere. We saw at least three 4x4s every day with at least one shooter that I should have taken, or couldn't get close enough to for a shot. On the second day my hunting buddy shot a 5x5 plus nice eye guards that was kind of thin, and just under 30 inches. I shot my 28 inch 4x4 on the third day and saw bigger bucks afterwards. The hardest thing on that hunt was not pulling the trigger. But I also let one go that might have been bigger, but didn't realize it until I watched the video of him back at home. The outfitter got divorced and moved away a few years after the hunt.
One buddy went there the next year and had very similar results. I have no idea who to book with, what's available or if it's still thick with mule deer, but it would be my first place to look if I was wanting to go again. He shot a heavy 25 inch wide 4x4 plus eye guards.
There where also quite a few pronghorn all over the place, but we didn't have tags and never spent much time glassing them.
This is the one that I shot