The best chance for a trophy goat is in Arizona.
But since we have more lopes than people . . . you have a good chance in most areas of getting a nice 14-15" lope. Glass from a high spot, chack near water holes/streams/tanks, also game trails at fence crossings. Lopes go under fences, not over. So they will use the same "fence crossing" time after time. In all the years I have hunted antelope, I can count on three fingers all the lopes I have seen jump over a fence.
You should also go to the "Public Land" link on the Wyo G&G site. Walk-in, HMA's, etc are listed there. They are private lands that allow public hunting (if you follow their rules!)
Good luck!!