Yes we do, it's just as pricey as the lamb from New Zealand, but it's local, certified grass fed/organic & seemingly tastier. You might find this link useful:
http://montananaturallamb.com/home.php
Chevon (young goat) is pretty tasty, affordable & easy to get if you know the right people; it's not offered in stores though.
Apparently most people don't like the flavour of adult sheep or goats. Older goat can be pretty gamy though, so I can't really blame John Q. Public for not liking it, but mutton isn't bad at all. I think it's just a flavour that most Americans are not accustomed to. One of these days I hope to have the space to raise my own mutton.
Regards, GF.