Why do people move from one county or region to another? The usual suspects are jobs, family, significant others, and overall cost of living, but there are other elements at play. For those with children, moving within close proximity of a highly rated school district is a key contributing factor. For younger adults just starting out, living someplace with a vibrant social scene might be a top priority. And for those whose careers have wound down after a lifetime of work, finding retirement-friendly communities is the goal—communities deemed to be safe, offer accessibility to medical resources and leisure activities in equal measure, and be affordable for those on a limited income.
This is, of course, by no means an exhaustive list. People's reasons for choosing to live where they do are as diverse as people themselves.
As far as why certain counties across the U.S. have experienced growth, relocation is not the sole, or even primary, reason why. While more than 1,800 counties saw population gains in 2021, approximately 73% of all U.S. counties saw what the U.S. Census Bureau characterizes as a natural decrease. This was a significant jump from 2020, when 55.5% of countries experienced such a decrease. According to the Bureau, natural decrease is the simple result of "when there are more deaths than births in a population over a given time period." In 2021, the conflation of fewer births with an aging population that was also absorbing a higher-than-usual mortality rate due to the ongoing COVID-19 pandemic led to this "increased decrease."
Nonetheless, as stated 1,800 counties nationwide have grown larger over the last year, and a sizable percentage of them are in Montana. Stacker compiled a list of the fastest-growing counties in Montana using data from the U.S. Census Bureau. Counties are ranked by the highest population growth from 2010 to 2020, based on the U.S. Decennial Census.
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#50. Wheatland County
- 2010 to 2020 population change: -99
--- #1,629 among all counties nationwide
- 2010 to 2020 percent population change: -4.6%
--- #49 among counties in Montana, #2,254 among all counties nationwide
- 2020 population: 2,069
--- #43 largest county in Montana, #3,035 largest county nationwide
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#49. Prairie County
- 2010 to 2020 population change: -91
--- #1,622 among all counties nationwide
- 2010 to 2020 percent population change: -7.7%
--- #53 among counties in Montana, #2,692 among all counties nationwide
- 2020 population: 1,088
--- #52 largest county in Montana, #3,103 largest county nationwide
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#48. Daniels County
- 2010 to 2020 population change: -90
--- #1,621 among all counties nationwide
- 2010 to 2020 percent population change: -5.1%
--- #50 among counties in Montana, #2,350 among all counties nationwide
- 2020 population: 1,661
--- #49 largest county in Montana, #3,070 largest county nationwide
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#47. Powell County
- 2010 to 2020 population change: -81
--- #1,600 among all counties nationwide
- 2010 to 2020 percent population change: -1.2%
--- #42 among counties in Montana, #1,680 among all counties nationwide
- 2020 population: 6,946
--- #30 largest county in Montana, #2,665 largest county nationwide
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#46. Wibaux County
- 2010 to 2020 population change: -80
--- #1,597 among all counties nationwide
- 2010 to 2020 percent population change: -7.9%
--- #54 among counties in Montana, #2,704 among all counties nationwide
- 2020 population: 937
--- #53 largest county in Montana, #3,107 largest county nationwide
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#45. Golden Valley County
- 2010 to 2020 population change: -61
--- #1,576 among all counties nationwide
- 2010 to 2020 percent population change: -6.9%
--- #52 among counties in Montana, #2,598 among all counties nationwide
- 2020 population: 823
--- #54 largest county in Montana, #3,114 largest county nationwide
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#44. Judith Basin County
- 2010 to 2020 population change: -49
--- #1,555 among all counties nationwide
- 2010 to 2020 percent population change: -2.4%
--- #45 among counties in Montana, #1,903 among all counties nationwide
- 2020 population: 2,023
--- #44 largest county in Montana, #3,037 largest county nationwide
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#43. Powder River County
- 2010 to 2020 population change: -49
--- #1,555 among all counties nationwide
- 2010 to 2020 percent population change: -2.8%
--- #47 among counties in Montana, #1,969 among all counties nationwide
- 2020 population: 1,694
--- #48 largest county in Montana, #3,067 largest county nationwide
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#42. Phillips County
- 2010 to 2020 population change: -36
--- #1,537 among all counties nationwide
- 2010 to 2020 percent population change: -0.8%
--- #41 among counties in Montana, #1,622 among all counties nationwide
- 2020 population: 4,217
--- #38 largest county in Montana, #2,870 largest county nationwide
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#41. Garfield County
- 2010 to 2020 population change: -33
--- #1,530 among all counties nationwide
- 2010 to 2020 percent population change: -2.7%
--- #46 among counties in Montana, #1,962 among all counties nationwide
- 2020 population: 1,173
--- #51 largest county in Montana, #3,099 largest county nationwide
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#40. Dawson County
- 2010 to 2020 population change: -26
--- #1,524 among all counties nationwide
- 2010 to 2020 percent population change: -0.3%
--- #40 among counties in Montana, #1,545 among all counties nationwide
- 2020 population: 8,940
--- #25 largest county in Montana, #2,495 largest county nationwide
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#39. Lincoln County
- 2010 to 2020 population change: -10
--- #1,502 among all counties nationwide
- 2010 to 2020 percent population change: -0.1%
--- #38 among counties in Montana, #1,498 among all counties nationwide
- 2020 population: 19,677
--- #10 largest county in Montana, #1,834 largest county nationwide
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#38. McCone County
- 2010 to 2020 population change: -5
--- #1,498 among all counties nationwide
- 2010 to 2020 percent population change: -0.3%
--- #39 among counties in Montana, #1,544 among all counties nationwide
- 2020 population: 1,729
--- #47 largest county in Montana, #3,064 largest county nationwide
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#37. Petroleum County
- 2010 to 2020 population change: +2
--- #1,489 among all counties nationwide
- 2010 to 2020 percent population change: +0.4%
--- #37 among counties in Montana, #1,426 among all counties nationwide
- 2020 population: 496
--- #56 largest county in Montana, #3,135 largest county nationwide
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#36. Sweet Grass County
- 2010 to 2020 population change: +27
--- #1,456 among all counties nationwide
- 2010 to 2020 percent population change: +0.7%
--- #36 among counties in Montana, #1,371 among all counties nationwide
- 2020 population: 3,678
--- #39 largest county in Montana, #2,911 largest county nationwide
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#35. Meagher County
- 2010 to 2020 population change: +36
--- #1,448 among all counties nationwide
- 2010 to 2020 percent population change: +1.9%
--- #30 among counties in Montana, #1,201 among all counties nationwide
- 2020 population: 1,927
--- #46 largest county in Montana, #3,046 largest county nationwide
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#34. Treasure County
- 2010 to 2020 population change: +44
--- #1,437 among all counties nationwide
- 2010 to 2020 percent population change: +6.1%
--- #17 among counties in Montana, #696 among all counties nationwide
- 2020 population: 762
--- #55 largest county in Montana, #3,119 largest county nationwide
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#33. Chouteau County
- 2010 to 2020 population change: +82
--- #1,409 among all counties nationwide
- 2010 to 2020 percent population change: +1.4%
--- #32 among counties in Montana, #1,263 among all counties nationwide
- 2020 population: 5,895
--- #34 largest county in Montana, #2,744 largest county nationwide
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#32. Deer Lodge County
- 2010 to 2020 population change: +123
--- #1,378 among all counties nationwide
- 2010 to 2020 percent population change: +1.3%
--- #35 among counties in Montana, #1,280 among all counties nationwide
- 2020 population: 9,421
--- #22 largest county in Montana, #2,461 largest county nationwide
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#31. Beaverhead County
- 2010 to 2020 population change: +125
--- #1,375 among all counties nationwide
- 2010 to 2020 percent population change: +1.4%
--- #33 among counties in Montana, #1,272 among all counties nationwide
- 2020 population: 9,371
--- #23 largest county in Montana, #2,465 largest county nationwide
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#30. Teton County
- 2010 to 2020 population change: +153
--- #1,356 among all counties nationwide
- 2010 to 2020 percent population change: +2.5%
--- #28 among counties in Montana, #1,114 among all counties nationwide
- 2020 population: 6,226
--- #32 largest county in Montana, #2,720 largest county nationwide
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#29. Sheridan County
- 2010 to 2020 population change: +155
--- #1,354 among all counties nationwide
- 2010 to 2020 percent population change: +4.6%
--- #20 among counties in Montana, #865 among all counties nationwide
- 2020 population: 3,539
--- #40 largest county in Montana, #2,917 largest county nationwide
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#28. Fallon County
- 2010 to 2020 population change: +159
--- #1,351 among all counties nationwide
- 2010 to 2020 percent population change: +5.5%
--- #19 among counties in Montana, #770 among all counties nationwide
- 2020 population: 3,049
--- #42 largest county in Montana, #2,956 largest county nationwide
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#27. Custer County
- 2010 to 2020 population change: +168
--- #1,347 among all counties nationwide
- 2010 to 2020 percent population change: +1.4%
--- #31 among counties in Montana, #1,260 among all counties nationwide
- 2020 population: 11,867
--- #17 largest county in Montana, #2,290 largest county nationwide
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#26. Musselshell County
- 2010 to 2020 population change: +192
--- #1,336 among all counties nationwide
- 2010 to 2020 percent population change: +4.2%
--- #21 among counties in Montana, #903 among all counties nationwide
- 2020 population: 4,730
--- #36 largest county in Montana, #2,837 largest county nationwide
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#25. Valley County
- 2010 to 2020 population change: +209
--- #1,323 among all counties nationwide
- 2010 to 2020 percent population change: +2.8%
--- #25 among counties in Montana, #1,080 among all counties nationwide
- 2020 population: 7,578
--- #28 largest county in Montana, #2,611 largest county nationwide
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#24. Hill County
- 2010 to 2020 population change: +213
--- #1,318 among all counties nationwide
- 2010 to 2020 percent population change: +1.3%
--- #34 among counties in Montana, #1,278 among all counties nationwide
- 2020 population: 16,309
--- #12 largest county in Montana, #2,015 largest county nationwide
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#23. Granite County
- 2010 to 2020 population change: +230
--- #1,309 among all counties nationwide
- 2010 to 2020 percent population change: +7.5%
--- #15 among counties in Montana, #599 among all counties nationwide
- 2020 population: 3,309
--- #41 largest county in Montana, #2,939 largest county nationwide
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#22. Carter County
- 2010 to 2020 population change: +255
--- #1,292 among all counties nationwide
- 2010 to 2020 percent population change: +22.0%
--- #2 among counties in Montana, #89 among all counties nationwide
- 2020 population: 1,415
--- #50 largest county in Montana, #3,085 largest county nationwide
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#21. Big Horn County
- 2010 to 2020 population change: +259
--- #1,289 among all counties nationwide
- 2010 to 2020 percent population change: +2.0%
--- #29 among counties in Montana, #1,182 among all counties nationwide
- 2020 population: 13,124
--- #14 largest county in Montana, #2,207 largest county nationwide
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#20. Mineral County
- 2010 to 2020 population change: +312
--- #1,251 among all counties nationwide
- 2010 to 2020 percent population change: +7.4%
--- #16 among counties in Montana, #605 among all counties nationwide
- 2020 population: 4,535
--- #37 largest county in Montana, #2,853 largest county nationwide
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#19. Roosevelt County
- 2010 to 2020 population change: +369
--- #1,220 among all counties nationwide
- 2010 to 2020 percent population change: +3.5%
--- #24 among counties in Montana, #981 among all counties nationwide
- 2020 population: 10,794
--- #20 largest county in Montana, #2,362 largest county nationwide
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#18. Glacier County
- 2010 to 2020 population change: +379
--- #1,215 among all counties nationwide
- 2010 to 2020 percent population change: +2.8%
--- #26 among counties in Montana, #1,082 among all counties nationwide
- 2020 population: 13,778
--- #13 largest county in Montana, #2,168 largest county nationwide
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#17. Carbon County
- 2010 to 2020 population change: +395
--- #1,208 among all counties nationwide
- 2010 to 2020 percent population change: +3.9%
--- #22 among counties in Montana, #936 among all counties nationwide
- 2020 population: 10,473
--- #21 largest county in Montana, #2,381 largest county nationwide
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#16. Blaine County
- 2010 to 2020 population change: +553
--- #1,133 among all counties nationwide
- 2010 to 2020 percent population change: +8.5%
--- #12 among counties in Montana, #517 among all counties nationwide
- 2020 population: 7,044
--- #29 largest county in Montana, #2,654 largest county nationwide
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#15. Jefferson County
- 2010 to 2020 population change: +679
--- #1,098 among all counties nationwide
- 2010 to 2020 percent population change: +6.0%
--- #18 among counties in Montana, #724 among all counties nationwide
- 2020 population: 12,085
--- #16 largest county in Montana, #2,272 largest county nationwide
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#14. Madison County
- 2010 to 2020 population change: +932
--- #1,018 among all counties nationwide
- 2010 to 2020 percent population change: +12.1%
--- #6 among counties in Montana, #318 among all counties nationwide
- 2020 population: 8,623
--- #26 largest county in Montana, #2,521 largest county nationwide
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#13. Silver Bow County
- 2010 to 2020 population change: +933
--- #1,017 among all counties nationwide
- 2010 to 2020 percent population change: +2.7%
--- #27 among counties in Montana, #1,091 among all counties nationwide
- 2020 population: 35,133
--- #8 largest county in Montana, #1,299 largest county nationwide
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#12. Sanders County
- 2010 to 2020 population change: +987
--- #1,002 among all counties nationwide
- 2010 to 2020 percent population change: +8.6%
--- #11 among counties in Montana, #506 among all counties nationwide
- 2020 population: 12,400
--- #15 largest county in Montana, #2,248 largest county nationwide
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#11. Broadwater County
- 2010 to 2020 population change: +1,162
--- #966 among all counties nationwide
- 2010 to 2020 percent population change: +20.7%
--- #3 among counties in Montana, #102 among all counties nationwide
- 2020 population: 6,774
--- #31 largest county in Montana, #2,674 largest county nationwide
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#10. Park County
- 2010 to 2020 population change: +1,555
--- #891 among all counties nationwide
- 2010 to 2020 percent population change: +9.9%
--- #9 among counties in Montana, #424 among all counties nationwide
- 2020 population: 17,191
--- #11 largest county in Montana, #1,957 largest county nationwide
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#9. Richland County
- 2010 to 2020 population change: +1,745
--- #857 among all counties nationwide
- 2010 to 2020 percent population change: +17.9%
--- #4 among counties in Montana, #151 among all counties nationwide
- 2020 population: 11,491
--- #18 largest county in Montana, #2,317 largest county nationwide
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#8. Lake County
- 2010 to 2020 population change: +2,388
--- #764 among all counties nationwide
- 2010 to 2020 percent population change: +8.3%
--- #13 among counties in Montana, #535 among all counties nationwide
- 2020 population: 31,134
--- #9 largest county in Montana, #1,396 largest county nationwide
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#7. Cascade County
- 2010 to 2020 population change: +3,087
--- #695 among all counties nationwide
- 2010 to 2020 percent population change: +3.8%
--- #23 among counties in Montana, #954 among all counties nationwide
- 2020 population: 84,414
--- #5 largest county in Montana, #681 largest county nationwide
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#6. Ravalli County
- 2010 to 2020 population change: +3,962
--- #630 among all counties nationwide
- 2010 to 2020 percent population change: +9.9%
--- #10 among counties in Montana, #431 among all counties nationwide
- 2020 population: 44,174
--- #7 largest county in Montana, #1,094 largest county nationwide
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#5. Lewis and Clark County
- 2010 to 2020 population change: +7,578
--- #498 among all counties nationwide
- 2010 to 2020 percent population change: +12.0%
--- #7 among counties in Montana, #326 among all counties nationwide
- 2020 population: 70,973
--- #6 largest county in Montana, #767 largest county nationwide
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#4. Missoula County
- 2010 to 2020 population change: +8,623
--- #461 among all counties nationwide
- 2010 to 2020 percent population change: +7.9%
--- #14 among counties in Montana, #574 among all counties nationwide
- 2020 population: 117,922
--- #3 largest county in Montana, #533 largest county nationwide
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#3. Flathead County
- 2010 to 2020 population change: +13,429
--- #365 among all counties nationwide
- 2010 to 2020 percent population change: +14.8%
--- #5 among counties in Montana, #233 among all counties nationwide
- 2020 population: 104,357
--- #4 largest county in Montana, #584 largest county nationwide
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#2. Yellowstone County
- 2010 to 2020 population change: +16,759
--- #326 among all counties nationwide
- 2010 to 2020 percent population change: +11.3%
--- #8 among counties in Montana, #356 among all counties nationwide
- 2020 population: 164,731
--- #1 largest county in Montana, #406 largest county nationwide
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#1. Gallatin County
- 2010 to 2020 population change: +29,447
--- #220 among all counties nationwide
- 2010 to 2020 percent population change: +32.9%
--- #1 among counties in Montana, #28 among all counties nationwide
- 2020 population: 118,960
--- #2 largest county in Montana, #528 largest county nationwide
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