Are they hard to find in Montana? I know here in MD and in Michigan there are tons of places that make and sell them.
This is what I would do:
The Yellow pages would be a good start; maybe go to the local 7-11 and look for an Equipment Trader weekly magazine.
If you see a trailer you admire, look for a sticker on it from the OEM or dealer and call them.
Since you've got internet access, do an internet search at google or yahoo, or your favorite search engine and search for "equipment trailer montana" or something like that. You should get lots of hits on new trailer dealers in Montana.
hth