RANKING · 2020 CENSUS · 56 SHOWN OF 56

Fastest shrinking, Montana counties

Montana counties with the steepest population decline since the prior decennial census. This list covers the 56 counties in Montana that qualify, ranked against each other statewide.

Flip the list · Fastest growing, US counties →

MontanaAll states All rankings

SAME RANKING BYCities States Metros

RELATEDLargest by population Fastest growing Most densely populated Most sparsely populated Best broadband access Worst broadband access

YEAR2000 2010 2020

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Liberty County, MTMT1,957-16.2%+172%

02Rosebud County, MTMT8,253-9.8%−8%

03Wibaux County, MTMT885-7.9%−24%

04Prairie County, MTMT1,112-7.7%−42%

05Golden Valley County, MTMT844-6.9%−148%

06Toole County, MTMT5,211-6.6%−251%

07Daniels County, MTMT1,612-5.1%−53%

08Wheatland County, MTMT2,100-4.6%−889%

09Pondera County, MTMT6,072-4.1%+2862%

10Powder River County, MTMT1,781-2.8%−75%

11Garfield County, MTMT1,148-2.7%−86%

12Judith Basin County, MTMT2,162-2.4%−215%

13Stillwater County, MTMT9,445-1.7%−107%

14Fergus County, MTMT11,825-1.2%−23%

15Powell County, MTMT7,157-1.2%−114%

16Phillips County, MTMT4,203-0.8%−92%

17Dawson County, MTMT8,692-0.3%−94%

18McCone County, MTMT1,720-0.3%−98%

19Lincoln County, MTMT22,328-0.1%−101%

20Petroleum County, MTMT548+0.4%−108%

21Sweet Grass County, MTMT3,762+0.7%−95%

22Deer Lodge County, MTMT9,709+1.3%−116%

23Hill County, MTMT16,167+1.3%−124%

24Beaverhead County, MTMT10,043+1.4%−85%

25Chouteau County, MTMT5,865+1.4%−85%

26Custer County, MTMT12,034+1.4%−16897%

27Meagher County, MTMT2,137+1.9%−69%

28Big Horn County, MTMT12,752+2.0%−83%

29Teton County, MTMT6,496+2.5%−9%

30Silver Bow County, MTMT36,118+2.7%+39%

31Glacier County, MTMT13,463+2.8%−70%

32Valley County, MTMT7,385+2.8%−141%

33Roosevelt County, MTMT10,242+3.5%−203%

34Cascade County, MTMT85,029+3.8%+11%

35Carbon County, MTMT11,466+3.9%−78%

36Musselshell County, MTMT5,582+4.2%−56%

37Sheridan County, MTMT3,436+4.6%−135%

38Fallon County, MTMT2,959+5.5%−164%

39Jefferson County, MTMT13,329+6.0%−78%

40Treasure County, MTMT728+6.1%−512%

41Mineral County, MTMT5,185+7.4%−57%

42Granite County, MTMT3,658+7.5%−33%

43Missoula County, MTMT123,513+7.9%−64%

44Lake County, MTMT33,392+8.3%−68%

45Blaine County, MTMT6,860+8.5%+104%

46Sanders County, MTMT14,062+8.6%−52%

47Ravalli County, MTMT48,582+9.9%−78%

48Park County, MTMT18,214+9.9%+28%

49Yellowstone County, MTMT172,692+11.3%−19%

50Lewis and Clark County, MTMT75,331+12.0%−31%

51Madison County, MTMT10,026+12.1%−16%

52Flathead County, MTMT115,429+14.8%−43%

53Richland County, MTMT11,377+17.9%−283%

54Broadwater County, MTMT8,493+20.7%−36%

55Carter County, MTMT1,383+22.0%−331%

56Gallatin County, MTMT128,740+32.9%−4%

SHOWING 1–56 OF 56

Download CSV (full list, 56 rows)

UPDATED 2026-06-02 · DATA: US CENSUS BUREAU ACS 5-YEAR ESTIMATES