A small greenhouse with an aquaculture set up would be the way to go in the mtns in my opinion. My experience with aquaculture has shown a huge growth jump over plants grown in other manners. Your fertilizer is self replacing and you get the added benefit of meat.

As far as growing grains go, i'm not sure you could grow enough to make a loaf of bread reliably. I could be wrong, but it might be worth a try from someone already living in the mtns to see what they come up with. Be worth knowing before you actually had to grow them.

As far as livestock, I am a big fan of goats. They can feed and thrive in areas that a lot of other livestock would never thrive in. Plus you can get milk and make cheese from them. I am a big fan of ducks over chickens for eggs. We have ducks now and have averaged over 300 eggs each a year from our girls.