| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Biddle | city | Montana | United States | 45.10 | -105.34 | 3349 | |
| Biem | city | Montana | United States | 48.48 | -104.94 | 2509 | |
| Big Arm | city | Montana | United States | 47.80 | -114.29 | 3349 | |
| Big Arm Mobile Home Park | city | Montana | United States | 47.80 | -114.30 | 3349 | |
| Big Foot (historical) | city | Montana | United States | 46.12 | -112.15 | 5869 | |
| Big Mountain Trailer Park | city | Montana | United States | 48.42 | -114.34 | 3349 | |
| Big Pines Mobile Court | city | Montana | United States | 46.88 | -113.90 | 3349 | |
| Big Sag | city | Montana | United States | 47.60 | -110.71 | 3556 | |
| Big Sandy | city | Montana | United States | 48.18 | -110.11 | 2742 | |
| Big Sandy Trailer Court | city | Montana | United States | 48.18 | -110.11 | 2742 | |
| Big Sky | city | Montana | United States | 45.28 | -111.37 | 6797 | |
| Big Sky Canyon Village | city | Montana | United States | 45.26 | -111.25 | 6709 | |
| Big Sky Colonial Manor | city | Montana | United States | 48.37 | -114.20 | 3349 | |
| Big Sky Colony | city | Montana | United States | 48.85 | -112.78 | 4297 | |
| Big Sky Meadow Village | city | Montana | United States | 45.27 | -111.30 | 6207 | |
| Big Sky Mobile Home Court | city | Montana | United States | 45.27 | -111.33 | 6709 | |
| Big Sky Mobile Home Park | city | Montana | United States | 46.21 | -114.15 | 4189 | |
| Big Sky Mountain Village | city | Montana | United States | 45.29 | -111.40 | 7549 | |
| Big Stone Colony | city | Montana | United States | 47.40 | -111.22 | 3740 | |
| Big Timber | city | Montana | United States | 45.83 | -109.96 | 4199 | |
| Big Warm (historical) | city | Montana | United States | 48.02 | -108.45 | 3349 | |
| Bigfork | city | Montana | United States | 48.06 | -114.07 | 3349 | |
| Bighorn | city | Montana | United States | 46.16 | -107.45 | 2726 | |
| Bill Bracket Place | city | Montana | United States | 46.26 | -110.59 | 6177 | |
| Billings | city | Montana | United States | 45.78 | -108.50 | 3349 | |
| Billings Heights | city | Montana | United States | 45.83 | -108.46 | 3349 | |
| Billings Metropolitan Area | city | Montana | United States | 45.78 | -108.50 | 3349 | |
| Bing | city | Montana | United States | 46.44 | -114.08 | 3398 | |
| Birch Creek (historical) | city | Montana | United States | 45.41 | -112.71 | 5400 | |
| Birch Creek Colony | city | Montana | United States | 48.25 | -112.47 | 4189 | |
| Birdseye | city | Montana | United States | 46.67 | -112.15 | 4199 | |
| Birney | city | Montana | United States | 45.32 | -106.52 | 3349 | |
| Birney Day School | city | Montana | United States | 45.42 | -106.47 | 3349 | |
| Bisel | city | Montana | United States | 45.71 | -111.08 | 5029 | |
| Bishop Place | city | Montana | United States | 45.22 | -112.49 | 5456 | |
| Bison | city | Montana | United States | 48.39 | -113.27 | 5200 | |
| Bitter Root (historical) | city | Montana | United States | 46.57 | -114.05 | 3398 | |
| Bitterroot Court | city | Montana | United States | 46.52 | -114.05 | 3569 | |
| Bitterroot Gateway Trailer Court | city | Montana | United States | 46.76 | -114.08 | 3349 | |
| Bitterroot Pines | city | Montana | United States | 46.64 | -114.08 | 3349 | |
| Bitterroot Trailer Court | city | Montana | United States | 48.54 | -109.65 | 2644 |