| Annual Estimates of the Population for Counties of Montana: April 1, 2000 to July 1, 2006 | |||||||||
| Geographic Area | Population Estimates | April 1, 2000 | |||||||
| July 1, 2006 | July 1, 2005 | July 1, 2004 | July 1, 2003 | July 1, 2002 | July 1, 2001 | July 1, 2000 | Estimates Base | Census | |
| Montana | 944,632 | 934,737 | 926,345 | 917,193 | 910,357 | 906,148 | 903,531 | 902,195 | 902,195 |
| Beaverhead County | 8,743 | 8,778 | 8,832 | 8,911 | 8,998 | 9,076 | 9,199 | 9,202 | 9,202 |
| Big Horn County | 13,035 | 13,076 | 13,056 | 12,885 | 12,831 | 12,818 | 12,675 | 12,671 | 12,671 |
| Blaine County | 6,615 | 6,634 | 6,659 | 6,763 | 6,816 | 6,824 | 6,987 | 7,009 | 7,009 |
| Broadwater County | 4,572 | 4,506 | 4,520 | 4,412 | 4,407 | 4,401 | 4,372 | 4,385 | 4,385 |
| Carbon County | 9,903 | 9,895 | 9,772 | 9,738 | 9,720 | 9,660 | 9,556 | 9,552 | 9,552 |
| Carter County | 1,321 | 1,320 | 1,334 | 1,329 | 1,358 | 1,362 | 1,349 | 1,360 | 1,360 |
| Cascade County | 79,385 | 79,490 | 79,874 | 79,736 | 79,738 | 79,858 | 80,240 | 80,357 | 80,357 |
| Chouteau County | 5,417 | 5,464 | 5,532 | 5,577 | 5,639 | 5,769 | 5,981 | 5,970 | 5,970 |
| Custer County | 11,151 | 11,256 | 11,414 | 11,342 | 11,431 | 11,471 | 11,665 | 11,696 | 11,696 |
| Daniels County | 1,774 | 1,825 | 1,837 | 1,914 | 1,932 | 2,013 | 2,012 | 2,017 | 2,017 |
| Dawson County | 8,624 | 8,629 | 8,643 | 8,732 | 8,731 | 8,916 | 9,044 | 9,059 | 9,059 |
| Deer Lodge County | 8,888 | 8,986 | 8,976 | 8,970 | 9,070 | 9,203 | 9,389 | 9,417 | 9,417 |
| Fallon County | 2,717 | 2,709 | 2,771 | 2,765 | 2,725 | 2,754 | 2,812 | 2,837 | 2,837 |
| Fergus County | 11,496 | 11,503 | 11,592 | 11,640 | 11,672 | 11,759 | 11,898 | 11,893 | 11,893 |
| Flathead County | 85,314 | 83,079 | 81,061 | 79,371 | 77,443 | 76,104 | 74,746 | 74,471 | 74,471 |
| Gallatin County | 80,921 | 78,262 | 75,608 | 73,282 | 71,078 | 69,804 | 68,285 | 67,831 | 67,831 |
| Garfield County | 1,244 | 1,211 | 1,229 | 1,237 | 1,244 | 1,262 | 1,268 | 1,279 | 1,279 |
| Glacier County | 13,578 | 13,522 | 13,519 | 13,283 | 13,197 | 13,129 | 13,208 | 13,247 | 13,247 |
| Golden Valley County | 1,150 | 1,146 | 1,103 | 1,052 | 1,065 | 1,015 | 1,023 | 1,042 | 1,042 |
| Granite County | 2,909 | 2,932 | 2,893 | 2,884 | 2,867 | 2,878 | 2,842 | 2,830 | 2,830 |
| Hill County | 16,403 | 16,276 | 16,345 | 16,263 | 16,355 | 16,530 | 16,636 | 16,673 | 16,673 |
| Jefferson County | 11,256 | 11,136 | 10,857 | 10,535 | 10,410 | 10,219 | 10,085 | 10,049 | 10,049 |
| Judith Basin County | 2,142 | 2,170 | 2,193 | 2,192 | 2,255 | 2,257 | 2,336 | 2,329 | 2,329 |
| Lake County | 28,606 | 28,275 | 27,915 | 27,364 | 27,001 | 26,948 | 26,632 | 26,507 | 26,507 |
| Lewis and Clark County | 59,302 | 58,387 | 57,897 | 57,123 | 56,452 | 56,254 | 55,883 | 55,716 | 55,716 |
| Liberty County | 1,863 | 1,967 | 2,029 | 2,041 | 2,020 | 2,103 | 2,150 | 2,158 | 2,158 |
| Lincoln County | 19,226 | 19,182 | 19,021 | 18,881 | 18,734 | 18,727 | 18,843 | 18,837 | 18,837 |
| McCone County | 1,760 | 1,776 | 1,785 | 1,807 | 1,841 | 1,900 | 1,966 | 1,977 | 1,977 |
| Madison County | 7,404 | 7,252 | 7,073 | 6,933 | 6,965 | 6,898 | 6,872 | 6,851 | 6,851 |
| Meagher County | 1,968 | 1,961 | 1,997 | 1,968 | 1,937 | 1,954 | 1,932 | 1,932 | 1,932 |
| Mineral County | 4,057 | 4,033 | 3,888 | 3,864 | 3,811 | 3,848 | 3,883 | 3,884 | 3,884 |
| Missoula County | 101,417 | 100,033 | 99,031 | 98,359 | 97,788 | 96,692 | 96,090 | 95,802 | 95,802 |
| Musselshell County | 4,586 | 4,474 | 4,494 | 4,482 | 4,459 | 4,445 | 4,500 | 4,497 | 4,497 |
| Park County | 16,084 | 15,965 | 15,760 | 15,763 | 15,830 | 15,726 | 15,728 | 15,694 | 15,694 |
| Petroleum County | 474 | 462 | 496 | 493 | 488 | 479 | 492 | 493 | 493 |
| Phillips County | 4,098 | 4,135 | 4,225 | 4,257 | 4,351 | 4,446 | 4,557 | 4,601 | 4,601 |
| Pondera County | 6,032 | 6,084 | 6,096 | 6,186 | 6,253 | 6,356 | 6,374 | 6,424 | 6,424 |
| Powder River County | 1,756 | 1,714 | 1,769 | 1,827 | 1,827 | 1,814 | 1,858 | 1,858 | 1,858 |
| Powell County | 6,997 | 6,968 | 6,898 | 6,937 | 7,037 | 7,058 | 7,183 | 7,180 | 7,180 |
| Prairie County | 1,074 | 1,090 | 1,137 | 1,163 | 1,185 | 1,213 | 1,187 | 1,199 | 1,199 |
| Ravalli County | 40,582 | 39,822 | 39,417 | 38,702 | 37,729 | 36,906 | 36,343 | 36,070 | 36,070 |
| Richland County | 9,295 | 9,163 | 9,071 | 9,166 | 9,271 | 9,443 | 9,628 | 9,667 | 9,667 |
| Roosevelt County | 10,496 | 10,601 | 10,610 | 10,410 | 10,432 | 10,574 | 10,626 | 10,620 | 10,620 |
| Rosebud County | 9,261 | 9,279 | 9,228 | 9,301 | 9,273 | 9,272 | 9,385 | 9,383 | 9,383 |
| Sanders County | 11,138 | 11,009 | 10,872 | 10,506 | 10,430 | 10,456 | 10,253 | 10,227 | 10,227 |
| Sheridan County | 3,447 | 3,517 | 3,639 | 3,652 | 3,804 | 3,945 | 4,081 | 4,105 | 4,105 |
| Silver Bow County | 32,801 | 32,876 | 33,038 | 33,193 | 33,431 | 33,766 | 34,527 | 34,606 | 34,606 |
| Stillwater County | 8,646 | 8,468 | 8,411 | 8,439 | 8,451 | 8,375 | 8,224 | 8,195 | 8,195 |
| Sweet Grass County | 3,760 | 3,698 | 3,698 | 3,612 | 3,624 | 3,607 | 3,636 | 3,609 | 3,609 |
| Teton County | 6,115 | 6,174 | 6,254 | 6,375 | 6,316 | 6,410 | 6,438 | 6,445 | 6,445 |
| Toole County | 5,073 | 5,174 | 5,227 | 5,303 | 5,415 | 5,341 | 5,261 | 5,267 | 5,267 |
| Treasure County | 680 | 694 | 738 | 743 | 774 | 819 | 854 | 861 | 861 |
| Valley County | 6,995 | 7,144 | 7,240 | 7,291 | 7,394 | 7,532 | 7,639 | 7,675 | 7,675 |
| Wheatland County | 1,959 | 2,025 | 2,054 | 2,098 | 2,168 | 2,160 | 2,252 | 2,259 | 2,259 |
| Wibaux County | 909 | 944 | 977 | 982 | 1,000 | 1,018 | 1,073 | 1,068 | 1,068 |
| Yellowstone County | 138,213 | 136,586 | 134,740 | 133,159 | 131,884 | 130,581 | 129,573 | 129,352 | 129,352 |
Source: Population Division, U.S. Census Bureau