General AT's run wide. Mud flavors are normally a little narrower in the tread for a given size. The cooper AT3's seem a little narrow in some sizes, but I'm not sure about 265. I don't recall what you wrote about rims, but running them on a 7" rim rather than an 8" will pull out some "section width" and make them appear skinnier.
I can also tell you that a 235/85 Cooper ST Maxx is a very wide 235... If I was going to give it a class, I would have called it a 255/80R16, which is more what you're asking for. But it is an E tire, and a heavy one at that, so probably out for you.
Look for a tire that doesn't have such a square shoulder profile. The BFG AT, General AT, and lots of others have a very square shoulder, which will make for a wider tread. The cooper AT3's are softer, which usually means a little narrower.
Happy shopping!
Good luck!