No, I wasn't able to find anything top-notch. I did a broad survey, however.
Best option I found was Hagen-Daaz from grocery stores. Other than that, there's a lot of that weird Nestle ice cream, with a lot of flavors with funny names (e.g. Moose Tracks) but not very high quality.
Enjoy the search, though!
If for some reason you end up on the east side of Glacier National Park, the Park Cafe in St. Mary has incredible pie.