I second the Carol Deppe recommendation! There's also some great (albeit more general) insight about selecting varieties for resilience in her other book,
The Resilient Gardener, which is available at the Missoula Public Library.
Also, there's a seed swap coming up, where I know people will be trading their own varieties specific to Montana. Here's the listing:
Missoula Seed Swap
WHEN: Feb 15, 4 to 7 pm (NOTE NEW TIME)...
WHERE: Stensrud Event Center, 314 N 1st W.
Potluck snacks. Hosted by the
Inland Northwest Permaculture Guild