RANKING · 2025 ESTIMATES · 56 SHOWN OF 56

Fastest growing, Montana counties

Montana counties ranked by population growth from the 2020 census to 2025. This list covers the 56 counties in Montana that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

RELATEDLargest by population Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Broadwater County, MTMT8,493+25.4%−21%

02Musselshell County, MTMT5,582+18.0%+89%

03Madison County, MTMT10,026+16.3%+13%

04Mineral County, MTMT5,185+14.3%−16%

05Lincoln County, MTMT22,328+13.5%+74%

06Sanders County, MTMT14,062+13.4%−25%

07Meagher County, MTMT2,137+10.9%+75%

08Flathead County, MTMT115,429+10.6%−59%

09Granite County, MTMT3,658+10.5%−5%

10Petroleum County, MTMT548+10.5%−309%

11Jefferson County, MTMT13,329+10.3%−61%

12Ravalli County, MTMT48,582+10.0%−77%

13Carbon County, MTMT11,466+9.5%−48%

14Gallatin County, MTMT128,740+8.2%−76%

15Lake County, MTMT33,392+7.3%−72%

16Beaverhead County, MTMT10,043+7.2%−22%

17Judith Basin County, MTMT2,162+6.9%+234%

18Lewis and Clark County, MTMT75,331+6.1%−65%

19Park County, MTMT18,214+6.0%−23%

20Stillwater County, MTMT9,445+5.4%−79%

21Powder River County, MTMT1,781+5.1%−146%

22Yellowstone County, MTMT172,692+4.8%−66%

23Toole County, MTMT5,211+4.8%+10%

24Missoula County, MTMT123,513+4.7%−78%

25Teton County, MTMT6,496+4.3%+56%

26Fergus County, MTMT11,825+3.3%−311%

27Deer Lodge County, MTMT9,709+3.1%−136%

28Powell County, MTMT7,157+3.0%−64%

29Pondera County, MTMT6,072+3.0%−2209%

30Silver Bow County, MTMT36,118+2.8%+43%

31Golden Valley County, MTMT844+2.6%−82%

32Sweet Grass County, MTMT3,762+2.3%−84%

33Prairie County, MTMT1,112+2.2%−117%

34Wheatland County, MTMT2,100+1.5%+159%

35Custer County, MTMT12,034+1.4%−16561%

36Cascade County, MTMT85,029+0.7%−79%

37Liberty County, MTMT1,957-0.1%−98%

38Phillips County, MTMT4,203-0.3%−97%

39Chouteau County, MTMT5,865-0.5%−105%

40McCone County, MTMT1,720-0.5%−96%

41Hill County, MTMT16,167-0.9%−84%

42Rosebud County, MTMT8,253-0.9%−91%

43Richland County, MTMT11,377-1.0%−90%

44Garfield County, MTMT1,148-2.1%−89%

45Carter County, MTMT1,383-2.3%−76%

46Glacier County, MTMT13,463-2.3%−125%

47Valley County, MTMT7,385-2.5%−63%

48Blaine County, MTMT6,860-2.6%−163%

49Dawson County, MTMT8,692-2.8%−41%

50Big Horn County, MTMT12,752-2.8%−124%

51Sheridan County, MTMT3,436-2.9%−78%

52Daniels County, MTMT1,612-3.0%−73%

53Fallon County, MTMT2,959-3.0%−66%

54Treasure County, MTMT728-4.5%+200%

55Roosevelt County, MTMT10,242-5.1%+48%

56Wibaux County, MTMT885-5.5%−46%

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU POPULATION ESTIMATES