RANKING · 2010 CENSUS · 56 SHOWN OF 56

Oldest by median age, Montana counties · 2010

Montana counties ranked by median age of residents (2023 ACS). This list covers the 56 counties in Montana that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros ZIP codes

RELATEDYoungest by median age Most foreign-born residents Highest uninsured rate Most women Most men Highest disability rate

YEAR1990 2000 2010 2020 2024

RANKPLACESTATEPOPMEDIAN AGEVS 2000

01Prairie County, MTMT1,11253.6+10%

02Granite County, MTMT3,65852.1+22%

03Treasure County, MTMT72851.5+23%

04Daniels County, MTMT1,61250.4+7%

05Sheridan County, MTMT3,43650.3+12%

06Carter County, MTMT1,38350.2+20%

07Meagher County, MTMT2,13750.1+17%

08Madison County, MTMT10,02649.8+15%

09Mineral County, MTMT5,18549.8+21%

10Sanders County, MTMT14,06249.8+13%

11Powder River County, MTMT1,78149.3+17%

12Musselshell County, MTMT5,58249.1+14%

13Wibaux County, MTMT88549.0+16%

14Lincoln County, MTMT22,32848.9+16%

15McCone County, MTMT1,72048.9+15%

16Golden Valley County, MTMT84448.8+18%

17Judith Basin County, MTMT2,16248.3+15%

18Carbon County, MTMT11,46648.1+15%

19Fergus County, MTMT11,82547.8+13%

20Petroleum County, MTMT54847.3+15%

21Phillips County, MTMT4,20346.8+15%

22Sweet Grass County, MTMT3,76246.6+13%

23Garfield County, MTMT1,14846.4+12%

24Valley County, MTMT7,38546.4+11%

25Jefferson County, MTMT13,32946.2+15%

26Deer Lodge County, MTMT9,70946.0+9%

27Ravalli County, MTMT48,58246.0+12%

28Teton County, MTMT6,49645.8+14%

29Stillwater County, MTMT9,44545.7+12%

30Broadwater County, MTMT8,49345.4+10%

31Park County, MTMT18,21445.4+12%

32Powell County, MTMT7,15745.1+14%

33Wheatland County, MTMT2,10044.9+8%

34Liberty County, MTMT1,95744.6+7%

35Dawson County, MTMT8,69243.5+6%

36Fallon County, MTMT2,95942.9+4%

37Pondera County, MTMT6,07242.8+11%

38Custer County, MTMT12,03442.1+7%

39Beaverhead County, MTMT10,04342.0+12%

40Chouteau County, MTMT5,86541.5+6%

41Toole County, MTMT5,21141.5+6%

42Lake County, MTMT33,39241.3+8%

43Richland County, MTMT11,37741.3+5%

44Silver Bow County, MTMT36,11841.3+6%

45Flathead County, MTMT115,42941.2+6%

46Lewis and Clark County, MTMT75,33140.9+8%

47Cascade County, MTMT85,02938.9+6%

48Yellowstone County, MTMT172,69238.3+4%

49Rosebud County, MTMT8,25336.5+6%

50Blaine County, MTMT6,86035.1+2%

51Hill County, MTMT16,16735.1+2%

52Missoula County, MTMT123,51334.3+3%

53Gallatin County, MTMT128,74032.5+6%

54Glacier County, MTMT13,46331.7+4%

55Roosevelt County, MTMT10,24231.6−2%

56Big Horn County, MTMT12,75230.5+2%

SHOWING 1–56 OF 56

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