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. The median across all 56 is +3.0%. Biggest climber in the top 100 since 2020: Carter County, MT, up 43 places to #12.

Flip the list · Fastest growing, US counties →

MontanaAll states All rankings

SAME RANKING BYCities States Metros

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01▲2Wibaux County, MTMT885-5.5%+4.8 pts

02▲31Roosevelt County, MTMT10,242-5.1%−1.7 pts

03▲37Treasure County, MTMT728-4.5%−3.0 pts

04▲34Fallon County, MTMT2,959-3.0%+5.6 pts

05▲2Daniels County, MTMT1,612-3.0%+8.0 pts

06▲31Sheridan County, MTMT3,436-2.9%+10.3 pts

07▲21Big Horn County, MTMT12,752-2.8%−14.6 pts

08▲9Dawson County, MTMT8,692-2.8%+1.9 pts

09▲36Blaine County, MTMT6,860-2.6%−6.8 pts

10▲22Valley County, MTMT7,385-2.5%+4.3 pts

11▲20Glacier County, MTMT13,463-2.3%−11.6 pts

12▲43Carter County, MTMT1,383-2.3%+7.3 pts

13▼2Garfield County, MTMT1,148-2.1%+17.4 pts

14▲39Richland County, MTMT11,377-1.0%+8.8 pts

15▼13Rosebud County, MTMT8,253-0.9%+9.8 pts

16▲7Hill County, MTMT16,167-0.9%+4.7 pts

17▲1McCone County, MTMT1,720-0.5%+12.6 pts

18▲7Chouteau County, MTMT5,865-0.5%−10.0 pts

19▼3Phillips County, MTMT4,203-0.3%+10.6 pts

20▼19Liberty County, MTMT1,957-0.1%+5.9 pts

21▲13Cascade County, MTMT85,029+0.7%−2.7 pts

22▲4Custer County, MTMT12,034+1.4%+1.4 pts

23▼15Wheatland County, MTMT2,100+1.5%+0.9 pts

24▼20Prairie County, MTMT1,112+2.2%+15.5 pts

25▼4Sweet Grass County, MTMT3,762+2.3%−12.1 pts

26▼21Golden Valley County, MTMT844+2.6%−11.7 pts

27▲3Silver Bow County, MTMT36,118+2.8%+0.8 pts

28▼19Pondera County, MTMT6,072+3.0%+3.1 pts

29▼14Powell County, MTMT7,157+3.0%−5.4 pts

30▼8Deer Lodge County, MTMT9,709+3.1%+11.4 pts

31▼17Fergus County, MTMT11,825+3.3%+4.9 pts

32▼3Teton County, MTMT6,496+4.3%+1.6 pts

33▲10Missoula County, MTMT123,513+4.7%−17.0 pts

34▼28Toole County, MTMT5,211+4.8%+0.4 pts

35▲14Yellowstone County, MTMT172,692+4.8%−9.2 pts

36▼26Powder River County, MTMT1,781+5.1%+16.2 pts

37▼24Stillwater County, MTMT9,445+5.4%−20.0 pts

38▲10Park County, MTMT18,214+6.0%−1.8 pts

39▲11Lewis and Clark County, MTMT75,331+6.1%−11.2 pts

40▼28Judith Basin County, MTMT2,162+6.9%+4.8 pts

41▼17Beaverhead County, MTMT10,043+7.2%−2.1 pts

42▲2Lake County, MTMT33,392+7.3%−18.7 pts

43▲13Gallatin County, MTMT128,740+8.2%−26.2 pts

44▼9Carbon County, MTMT11,466+9.5%−8.7 pts

45▲2Ravalli County, MTMT48,582+10.0%−34.2 pts

46▼7Jefferson County, MTMT13,329+10.3%−16.3 pts

47▼27Petroleum County, MTMT548+10.5%+15.5 pts

48▼6Granite County, MTMT3,658+10.5%−0.5 pts

49▲3Flathead County, MTMT115,429+10.6%−15.1 pts

50▼23Meagher County, MTMT2,137+10.9%+4.7 pts

51▼5Sanders County, MTMT14,062+13.4%−4.6 pts

52▼33Lincoln County, MTMT22,328+13.5%+5.7 pts

53▼12Mineral County, MTMT5,185+14.3%−2.8 pts

54▼3Madison County, MTMT10,026+16.3%+1.9 pts

55▼19Musselshell County, MTMT5,582+18.0%+8.5 pts

56▼2Broadwater County, MTMT8,493+25.4%−6.8 pts

SHOWING 1–56 OF 56

Download CSV (full list, 56 rows)

UPDATED 2026-09-11 · DATA: US CENSUS BUREAU POPULATION ESTIMATES