The south east section of the state doesn't have a whole lot of public access and it gets hunted pretty hard. I haven't worked my way over to the snowy mountains to call yet, but I know that south of there in Colorado can be productive. If you go a few hours north from Laramie it opens up to a lot more public.
On the side note mentioned above, my buddy said his dad and brother have lost some more calves this past couple weeks so we are going calling on their ranch this week. As soon as the coyotes stop taking calves and fawns I'll stop taking coyotes.