RANKING · 2010 CENSUS · 56 SHOWN OF 56

Fastest shrinking, Montana counties · 2010

Montana counties with the steepest population decline from the 2000 census to 2010. 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 growing Most population gained Most population lost Most densely populated Most sparsely populated

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Sheridan County, MTMT3,436-17.6%−4.3 pts

02Treasure County, MTMT728-16.6%−15.1 pts

03Golden Valley County, MTMT844-15.2%−29.4 pts

04Carter County, MTMT1,383-14.7%−5.2 pts

05Daniels County, MTMT1,612-13.2%−2.2 pts

06McCone County, MTMT1,720-12.3%+0.8 pts

07Judith Basin County, MTMT2,162-11.0%−13.1 pts

08Phillips County, MTMT4,203-7.6%+3.3 pts

09Blaine County, MTMT6,860-7.4%−11.6 pts

10Powder River County, MTMT1,781-6.2%+4.9 pts

11Teton County, MTMT6,496-5.8%−8.5 pts

12Garfield County, MTMT1,148-5.7%+13.8 pts

13Wibaux County, MTMT885-4.8%+5.6 pts

14Pondera County, MTMT6,072-4.2%−4.1 pts

15Wheatland County, MTMT2,100-4.0%−4.6 pts

16Valley County, MTMT7,385-4.0%+2.9 pts

17Hill County, MTMT16,167-3.5%+2.1 pts

18Chouteau County, MTMT5,865-2.6%−12.1 pts

19Fergus County, MTMT11,825-2.6%−1.0 pts

20Powell County, MTMT7,157-2.1%−10.6 pts

21Meagher County, MTMT2,137-2.1%−8.3 pts

22Roosevelt County, MTMT10,242-1.8%+1.6 pts

23Prairie County, MTMT1,112-1.7%+11.6 pts

24Rosebud County, MTMT8,253-1.6%+9.1 pts

25Deer Lodge County, MTMT9,709-1.3%+7.1 pts

26Silver Bow County, MTMT36,118-1.2%−3.1 pts

27Dawson County, MTMT8,692-1.0%+3.7 pts

28Park County, MTMT18,214-0.4%−8.1 pts

29Custer County, MTMT12,034+0.0%+0.0 pts

30Petroleum County, MTMT548+0.2%+5.2 pts

31Beaverhead County, MTMT10,043+0.5%−8.8 pts

32Richland County, MTMT11,377+0.8%+10.6 pts

33Musselshell County, MTMT5,582+0.9%−8.6 pts

34Toole County, MTMT5,211+1.1%−3.3 pts

35Glacier County, MTMT13,463+1.1%−8.1 pts

36Sweet Grass County, MTMT3,762+1.2%−13.3 pts

37Cascade County, MTMT85,029+1.2%−2.2 pts

38Big Horn County, MTMT12,752+1.5%−10.2 pts

39Fallon County, MTMT2,959+1.9%+10.4 pts

40Lincoln County, MTMT22,328+4.5%−3.2 pts

41Carbon County, MTMT11,466+5.5%−12.7 pts

42Liberty County, MTMT1,957+8.4%+14.4 pts

43Lake County, MTMT33,392+8.4%−17.5 pts

44Mineral County, MTMT5,185+8.7%−8.4 pts

45Granite County, MTMT3,658+8.8%−2.3 pts

46Stillwater County, MTMT9,445+11.3%−14.1 pts

47Ravalli County, MTMT48,582+11.5%−32.7 pts

48Sanders County, MTMT14,062+11.6%−6.4 pts

49Madison County, MTMT10,026+12.3%−2.1 pts

50Jefferson County, MTMT13,329+13.5%−13.1 pts

51Lewis and Clark County, MTMT75,331+13.8%−3.5 pts

52Missoula County, MTMT123,513+14.1%−7.7 pts

53Yellowstone County, MTMT172,692+14.4%+0.3 pts

54Flathead County, MTMT115,429+22.1%−3.7 pts

55Broadwater County, MTMT8,493+28.0%−4.2 pts

56Gallatin County, MTMT128,740+32.0%−2.5 pts

SHOWING 1–56 OF 56

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UPDATED 2026-08-08 · DATA: US CENSUS BUREAU DECENNIAL CENSUS