RANKING · 2025 ESTIMATES · 56 SHOWN OF 56

Fastest shrinking, Montana counties

Montana counties with the steepest population decline 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 growing Most population gained Most population lost Most densely populated Most sparsely populated

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Wibaux County, MTMT885-5.5%+4.8 pts

02Roosevelt County, MTMT10,242-5.1%−1.7 pts

03Treasure County, MTMT728-4.5%−3.0 pts

04Fallon County, MTMT2,959-3.0%+5.6 pts

05Daniels County, MTMT1,612-3.0%+8.0 pts

06Sheridan County, MTMT3,436-2.9%+10.3 pts

07Big Horn County, MTMT12,752-2.8%−14.6 pts

08Dawson County, MTMT8,692-2.8%+1.9 pts

09Blaine County, MTMT6,860-2.6%−6.8 pts

10Valley County, MTMT7,385-2.5%+4.3 pts

11Glacier County, MTMT13,463-2.3%−11.6 pts

12Carter County, MTMT1,383-2.3%+7.3 pts

13Garfield County, MTMT1,148-2.1%+17.4 pts

14Richland County, MTMT11,377-1.0%+8.8 pts

15Rosebud County, MTMT8,253-0.9%+9.8 pts

16Hill County, MTMT16,167-0.9%+4.7 pts

17McCone County, MTMT1,720-0.5%+12.6 pts

18Chouteau County, MTMT5,865-0.5%−10.0 pts

19Phillips County, MTMT4,203-0.3%+10.6 pts

20Liberty County, MTMT1,957-0.1%+5.9 pts

21Cascade County, MTMT85,029+0.7%−2.7 pts

22Custer County, MTMT12,034+1.4%+1.4 pts

23Wheatland County, MTMT2,100+1.5%+0.9 pts

24Prairie County, MTMT1,112+2.2%+15.5 pts

25Sweet Grass County, MTMT3,762+2.3%−12.1 pts

26Golden Valley County, MTMT844+2.6%−11.7 pts

27Silver Bow County, MTMT36,118+2.8%+0.8 pts

28Pondera County, MTMT6,072+3.0%+3.1 pts

29Powell County, MTMT7,157+3.0%−5.4 pts

30Deer Lodge County, MTMT9,709+3.1%+11.4 pts

31Fergus County, MTMT11,825+3.3%+4.9 pts

32Teton County, MTMT6,496+4.3%+1.6 pts

33Missoula County, MTMT123,513+4.7%−17.0 pts

34Toole County, MTMT5,211+4.8%+0.4 pts

35Yellowstone County, MTMT172,692+4.8%−9.2 pts

36Powder River County, MTMT1,781+5.1%+16.2 pts

37Stillwater County, MTMT9,445+5.4%−20.0 pts

38Park County, MTMT18,214+6.0%−1.8 pts

39Lewis and Clark County, MTMT75,331+6.1%−11.2 pts

40Judith Basin County, MTMT2,162+6.9%+4.8 pts

41Beaverhead County, MTMT10,043+7.2%−2.1 pts

42Lake County, MTMT33,392+7.3%−18.7 pts

43Gallatin County, MTMT128,740+8.2%−26.2 pts

44Carbon County, MTMT11,466+9.5%−8.7 pts

45Ravalli County, MTMT48,582+10.0%−34.2 pts

46Jefferson County, MTMT13,329+10.3%−16.3 pts

47Petroleum County, MTMT548+10.5%+15.5 pts

48Granite County, MTMT3,658+10.5%−0.5 pts

49Flathead County, MTMT115,429+10.6%−15.1 pts

50Meagher County, MTMT2,137+10.9%+4.7 pts

51Sanders County, MTMT14,062+13.4%−4.6 pts

52Lincoln County, MTMT22,328+13.5%+5.7 pts

53Mineral County, MTMT5,185+14.3%−2.8 pts

54Madison County, MTMT10,026+16.3%+1.9 pts

55Musselshell County, MTMT5,582+18.0%+8.5 pts

56Broadwater County, MTMT8,493+25.4%−6.8 pts

SHOWING 1–56 OF 56

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UPDATED 2026-08-08 · DATA: US CENSUS BUREAU POPULATION ESTIMATES