RANKING · 2020 CENSUS · 56 SHOWN OF 56

Fastest shrinking, Montana counties · 2020

Montana counties with the steepest population decline from the 2010 census to 2020. 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

01Liberty County, MTMT1,957-16.2%−10.3 pts

02Rosebud County, MTMT8,253-9.8%+0.9 pts

03Wibaux County, MTMT885-7.9%+2.5 pts

04Prairie County, MTMT1,112-7.7%+5.6 pts

05Golden Valley County, MTMT844-6.9%−21.2 pts

06Toole County, MTMT5,211-6.6%−11.0 pts

07Daniels County, MTMT1,612-5.1%+5.8 pts

08Wheatland County, MTMT2,100-4.6%−5.1 pts

09Pondera County, MTMT6,072-4.1%−4.0 pts

10Powder River County, MTMT1,781-2.8%+8.3 pts

11Garfield County, MTMT1,148-2.7%+16.8 pts

12Judith Basin County, MTMT2,162-2.4%−4.4 pts

13Stillwater County, MTMT9,445-1.7%−27.1 pts

14Fergus County, MTMT11,825-1.2%+0.4 pts

15Powell County, MTMT7,157-1.2%−9.6 pts

16Phillips County, MTMT4,203-0.8%+10.0 pts

17Dawson County, MTMT8,692-0.3%+4.4 pts

18McCone County, MTMT1,720-0.3%+12.8 pts

19Lincoln County, MTMT22,328-0.1%−7.8 pts

20Petroleum County, MTMT548+0.4%+5.4 pts

21Sweet Grass County, MTMT3,762+0.7%−13.7 pts

22Deer Lodge County, MTMT9,709+1.3%+9.7 pts

23Hill County, MTMT16,167+1.3%+6.9 pts

24Beaverhead County, MTMT10,043+1.4%−7.9 pts

25Chouteau County, MTMT5,865+1.4%−8.1 pts

26Custer County, MTMT12,034+1.4%+1.4 pts

27Meagher County, MTMT2,137+1.9%−4.3 pts

28Big Horn County, MTMT12,752+2.0%−9.8 pts

29Teton County, MTMT6,496+2.5%−0.3 pts

30Silver Bow County, MTMT36,118+2.7%+0.8 pts

31Glacier County, MTMT13,463+2.8%−6.5 pts

32Valley County, MTMT7,385+2.8%+9.7 pts

33Roosevelt County, MTMT10,242+3.5%+7.0 pts

34Cascade County, MTMT85,029+3.8%+0.4 pts

35Carbon County, MTMT11,466+3.9%−14.3 pts

36Musselshell County, MTMT5,582+4.2%−5.3 pts

37Sheridan County, MTMT3,436+4.6%+17.8 pts

38Fallon County, MTMT2,959+5.5%+14.1 pts

39Jefferson County, MTMT13,329+6.0%−20.6 pts

40Treasure County, MTMT728+6.1%+7.6 pts

41Mineral County, MTMT5,185+7.4%−9.8 pts

42Granite County, MTMT3,658+7.5%−3.6 pts

43Missoula County, MTMT123,513+7.9%−13.9 pts

44Lake County, MTMT33,392+8.3%−17.7 pts

45Blaine County, MTMT6,860+8.5%+4.3 pts

46Sanders County, MTMT14,062+8.6%−9.3 pts

47Ravalli County, MTMT48,582+9.9%−34.4 pts

48Park County, MTMT18,214+9.9%+2.2 pts

49Yellowstone County, MTMT172,692+11.3%−2.7 pts

50Lewis and Clark County, MTMT75,331+12.0%−5.4 pts

51Madison County, MTMT10,026+12.1%−2.3 pts

52Flathead County, MTMT115,429+14.8%−11.0 pts

53Richland County, MTMT11,377+17.9%+27.7 pts

54Broadwater County, MTMT8,493+20.7%−11.5 pts

55Carter County, MTMT1,383+22.0%+31.5 pts

56Gallatin County, MTMT128,740+32.9%−1.5 pts

SHOWING 1–56 OF 56

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