If you're looking for a feel-good Montana movie, there's no doubt that the film to rent is Big Eden. Completed in 2000, it's the story of a gay New Yorker who goes back home to Montana to take care of his ailing grandfather. There, he has the chance to finally become part of a real community, and perhaps to find love, as well.
Perhaps more fable than drama, there's no doubt that Big Eden is unrealistically rosy in its portrayal of small-town acceptance, but there's also no doubt that it's an engaging and heartwarming story. And the settings are among Montana's most gorgeous -- much of the movie was shot in Glacier Park, and if you've been to Swan Lake you'll recognize the general store in the film.
Here's a screencap from Big Eden's 4th of July celebration, which was filmed in Apgar. You can't help but recognize those mountains!