RANKING · 2025 ACS · 56 SHOWN OF 56

Most sparsely populated, Montana counties

Montana counties with the fewest residents per square mile (2023). 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 Fastest shrinking Most densely populated Best broadband access Worst broadband access

YEAR1990 2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION DENSITYVS 2000

01Garfield County, MTMT1,1480−10%

02Petroleum County, MTMT5480+11%

03Carter County, MTMT1,3830+2%

04Powder River County, MTMT1,7811−4%

05Prairie County, MTMT1,1121−7%

06McCone County, MTMT1,7201−13%

07Golden Valley County, MTMT8441−19%

08Treasure County, MTMT7281−15%

09Phillips County, MTMT4,2031−9%

10Meagher County, MTMT2,1371+11%

11Wibaux County, MTMT8851−17%

12Daniels County, MTMT1,6121−20%

13Judith Basin County, MTMT2,1621−7%

14Liberty County, MTMT1,9571−9%

15Wheatland County, MTMT2,1001−7%

16Chouteau County, MTMT5,8651−2%

17Valley County, MTMT7,3851−4%

18Blaine County, MTMT6,8602−2%

19Rosebud County, MTMT8,2532−12%

20Beaverhead County, MTMT10,0432+9%

21Fallon County, MTMT2,9592+4%

22Sweet Grass County, MTMT3,7622+4%

23Sheridan County, MTMT3,4362−16%

24Granite County, MTMT3,6582+29%

25Big Horn County, MTMT12,7523+1%

26Toole County, MTMT5,2113−1%

27Fergus County, MTMT11,8253−1%

28Madison County, MTMT10,0263+46%

29Teton County, MTMT6,4963+1%

30Musselshell County, MTMT5,5823+24%

31Powell County, MTMT7,1573−0%

32Custer County, MTMT12,0343+3%

33Dawson County, MTMT8,6924−4%

34Pondera County, MTMT6,0724−5%

35Mineral County, MTMT5,1854+33%

36Roosevelt County, MTMT10,2424−4%

37Glacier County, MTMT13,4634+2%

38Sanders County, MTMT14,0625+37%

39Stillwater County, MTMT9,4455+15%

40Richland County, MTMT11,3775+18%

41Hill County, MTMT16,1676−3%

42Carbon County, MTMT11,4666+20%

43Lincoln County, MTMT22,3286+19%

44Park County, MTMT18,2146+16%

45Broadwater County, MTMT8,4937+94%

46Jefferson County, MTMT13,3298+33%

47Deer Lodge County, MTMT9,70913+3%

48Ravalli County, MTMT48,58220+35%

49Lewis and Clark County, MTMT75,33122+35%

50Lake County, MTMT33,39222+26%

51Flathead County, MTMT115,42923+55%

52Cascade County, MTMT85,02932+6%

53Missoula County, MTMT123,51348+29%

54Gallatin County, MTMT128,74049+90%

55Silver Bow County, MTMT36,11850+4%

56Yellowstone County, MTMT172,69266+34%

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