If all else fails and you can actually go somewhere in Montana, I'm sure you could find a farmer that would fill your 5 or 10 gallon bucket right from the silo for a few bucks. Of course you'd have to malt it yourself, but that could be fun too.
My dad still grows wheat in North Texas, so at some point I'd like to do a wheat beer using his wheat that I've malted myself. Unfortunately no hops around there....