So I went online and found the population of Montana by county, and here's the breakdown of that map:
Griz Counties: 695,924 (69.2%)
Cat Counties: 222,130 (22.1%)
Divided Loyalty Counties: 86,384 (8.6%)
Unknown Loyalty County: 1,056 (0.1%)
Of the 10 most populous counties:
Griz Counties: 8
Cat Counties: 1
Divided Loyalty: 1
Of the 10 least populous counties:
Griz Counties: 2
Cat Counties: 5
Divided Loyalty: 2
Unknown Loyalty: 1
Of the Cat Counties, which have a total population of 222,130, Gallatin County accounts for 92,665 (41.7%).
Take out the counties with divided or unknown loyalty and compare just Griz vs. Cat Counties:
Griz Counties: 75.8%
Cat Counties: 24.2%