Montana Population By County in 2021
Updated on June 16, 2025.
Based on the US Census Vintage data estimates, in 2021, the population of Montana was 1,106,522. Among all Montana counties, Yellowstone had the highest population (167,448), followed by Gallatin (123,119), and Missoula (119,857). Petroleum was the least populated county (520).
Hover over or click on the counties in the map below to see the populations. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.
You can see similar information for other states and by state for the United States.
Related Topics: Montana Census Vintage Data Topic List.
Data Source: US Census Bureau (Vintage).
See this for other years:
Montana Population By County in 2021
Montana Population By County in 2021
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| County | Population | % of State Population |
|---|---|---|
| Beaverhead | 9551 | 0.86 |
| Big Horn | 12894 | 1.17 |
| Blaine | 6999 | 0.63 |
| Broadwater | 7327 | 0.66 |
| Carbon | 10900 | 0.99 |
| Carter | 1416 | 0.13 |
| Cascade | 84565 | 7.64 |
| Chouteau | 5939 | 0.54 |
| Custer | 11961 | 1.08 |
| Daniels | 1671 | 0.15 |
| Dawson | 8859 | 0.80 |
| Deer Lodge | 9522 | 0.86 |
| Fallon | 3011 | 0.27 |
| Fergus | 11619 | 1.05 |
| Flathead | 108790 | 9.83 |
| Gallatin | 123119 | 11.13 |
| Garfield | 1206 | 0.11 |
| Glacier | 13723 | 1.24 |
| Golden Valley | 816 | 0.07 |
| Granite | 3354 | 0.30 |
| Hill | 16207 | 1.47 |
| Jefferson | 12472 | 1.13 |
| Judith Basin | 2041 | 0.18 |
| Lake | 32081 | 2.90 |
| Lewis and Clark | 72517 | 6.55 |
| Liberty | 1937 | 0.18 |
| Lincoln | 20597 | 1.86 |
| McCone | 1710 | 0.16 |
| Madison | 8954 | 0.81 |
| Meagher | 1963 | 0.18 |
| Mineral | 4859 | 0.44 |
| Missoula | 119857 | 10.83 |
| Musselshell | 4910 | 0.44 |
| Park | 17525 | 1.58 |
| Petroleum | 520 | 0.05 |
| Phillips | 4209 | 0.38 |
| Pondera | 6017 | 0.54 |
| Powder River | 1707 | 0.15 |
| Powell | 7023 | 0.64 |
| Prairie | 1096 | 0.10 |
| Ravalli | 46096 | 4.17 |
| Richland | 11330 | 1.02 |
| Roosevelt | 10788 | 0.98 |
| Rosebud | 8082 | 0.73 |
| Sanders | 12949 | 1.17 |
| Sheridan | 3572 | 0.32 |
| Silver Bow | 35510 | 3.21 |
| Stillwater | 9026 | 0.82 |
| Sweet Grass | 3702 | 0.34 |
| Teton | 6279 | 0.57 |
| Toole | 4987 | 0.45 |
| Treasure | 768 | 0.07 |
| Valley | 7566 | 0.68 |
| Wheatland | 2039 | 0.18 |
| Wibaux | 936 | 0.09 |
| Yellowstone | 167448 | 15.13 |