The graph below ranks each Montana County by total residents according to the 2006 census estimates.
Montana total population by county
| County | Total Population |
| Yellowstone |  138,213 |
| Missoula | 101,417 |
| Flathead | 85,314 |
| Gallatin | 80,921 |
| Cascade | 79,385 |
| Lewis and Clark | 59,302 |
| Ravalli | 40,582 |
| Silver Bow | 32,801 |
| Lake | 28,606 |
| Lincoln | 19,226 |
| Hill | 16,403 |
| Park | 16,084 |
| Glacier | 13,578 |
| Big Horn | 13,035 |
| Fergus | 11,496 |
| Jefferson | 11,256 |
| Custer | 11,151 |
| Sanders | 11,138 |
| Roosevelt | 10,496 |
| Carbon | 9,903 |
| Richland | 9,295 |
| Rosebud | 9,261 |
| Deer Lodge | 8,888 |
| Beaverhead | 8,743 |
| Stillwater | 8,646 |
| Dawson | 8,624 |
| Madison | 7,404 |
| Powell | 6,997 |
| Valley | 6,995 |
| Blaine | 6,615 |
| Teton | 6,115 |
| Pondera | 6,032 |
| Chouteau | 5,417 |
| Toole | 5,073 |
| Musselshell | 4,586 |
| Broadwater | 4,572 |
| Phillips | 4,098 |
| Mineral | 4,057 |
| Sweet Grass | 3,760 |
| Sheridan | 3,447 |
| Granite | 2,909 |
| Fallon | 2,717 |
| Judith Basin | 2,142 |
| Meagher | 1,968 |
| Wheatland | 1,959 |
| Liberty | 1,863 |
| Daniels | 1,774 |
| McCone | 1,760 |
| Powder River | 1,756 |
| Carter | 1,321 |
| Garfield | 1,244 |
| Golden Valley | 1,150 |
| Prairie | 1,074 |
| Wibaux | 909 |
| Treasure | 680 |
| Petroleum | 474 |
| Yellowstone National Park | 0 |