RANKING · 2020 CENSUS · 56 SHOWN OF 56

Oldest by median age, Montana counties · 2020

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

01Sanders County, MTMT14,06255.2+25%

02Lincoln County, MTMT22,32854.0+28%

03Petroleum County, MTMT54853.4+30%

04Meagher County, MTMT2,13753.2+24%

05Golden Valley County, MTMT84453.1+28%

06Madison County, MTMT10,02652.9+22%

07Mineral County, MTMT5,18552.8+28%

08Prairie County, MTMT1,11252.8+8%

09Granite County, MTMT3,65852.6+23%

10Judith Basin County, MTMT2,16251.4+22%

11Musselshell County, MTMT5,58251.3+19%

12Powder River County, MTMT1,78150.8+21%

13Ravalli County, MTMT48,58250.2+22%

14Carbon County, MTMT11,46650.0+19%

15Deer Lodge County, MTMT9,70949.4+17%

16Jefferson County, MTMT13,32949.2+22%

17Stillwater County, MTMT9,44548.6+19%

18Sweet Grass County, MTMT3,76248.4+17%

19Wibaux County, MTMT88547.8+13%

20Fergus County, MTMT11,82547.5+12%

21Wheatland County, MTMT2,10047.2+14%

22Park County, MTMT18,21446.9+16%

23McCone County, MTMT1,72046.2+9%

24Sheridan County, MTMT3,43646.0+2%

25Powell County, MTMT7,15745.9+16%

26Daniels County, MTMT1,61245.8−3%

27Broadwater County, MTMT8,49345.7+11%

28Teton County, MTMT6,49645.1+13%

29Treasure County, MTMT72845.0+8%

30Garfield County, MTMT1,14844.9+8%

31Lake County, MTMT33,39244.7+17%

32Phillips County, MTMT4,20344.7+10%

33Valley County, MTMT7,38544.1+6%

34Beaverhead County, MTMT10,04343.9+17%

35Carter County, MTMT1,38343.1+3%

36Flathead County, MTMT115,42942.9+10%

37Pondera County, MTMT6,07242.1+9%

38Liberty County, MTMT1,95742.1+1%

39Silver Bow County, MTMT36,11841.8+7%

40Dawson County, MTMT8,69241.3+1%

41Lewis and Clark County, MTMT75,33141.3+9%

42Custer County, MTMT12,03441.0+4%

43Toole County, MTMT5,21141.0+5%

44Chouteau County, MTMT5,86540.3+3%

45Rosebud County, MTMT8,25339.3+14%

46Fallon County, MTMT2,95939.0−5%

47Cascade County, MTMT85,02938.9+6%

48Yellowstone County, MTMT172,69238.8+5%

49Richland County, MTMT11,37738.4−2%

50Missoula County, MTMT123,51337.7+14%

51Hill County, MTMT16,16735.3+2%

52Blaine County, MTMT6,86034.5+0%

53Gallatin County, MTMT128,74033.4+9%

54Roosevelt County, MTMT10,24233.2+3%

55Glacier County, MTMT13,46332.8+7%

56Big Horn County, MTMT12,75231.5+6%

SHOWING 1–56 OF 56

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