RANKING · 2010 CENSUS · 56 SHOWN OF 56

Oldest by median age, Montana counties · 2010

Montana counties ranked by median age of residents (2010 ACS). This list covers the 56 counties in Montana that qualify, ranked against each other statewide. The median across all 56 is 45.8.

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SAME RANKING BYCities States Metros ZIP codes

RELATEDLargest foreign-born population Most residents with a disability Largest veteran population Most uninsured people Largest senior population Most unmarried people

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 2026-09-11 · DATA: US CENSUS BUREAU DECENNIAL CENSUS