RANKING · 2024 ACS · 56 SHOWN OF 56

Oldest by median age, Montana counties

Montana counties ranked by median age of residents (2024 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

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

01Meagher County, MTMT2,13758.3+36%

02Prairie County, MTMT1,11257.8+18%

03Carter County, MTMT1,38356.9+36%

04Sanders County, MTMT14,06254.6+24%

05Daniels County, MTMT1,61253.4+14%

06McCone County, MTMT1,72053.2+25%

07Granite County, MTMT3,65853.0+24%

08Lincoln County, MTMT22,32852.8+25%

09Madison County, MTMT10,02652.2+20%

10Treasure County, MTMT72852.0+24%

11Petroleum County, MTMT54851.6+26%

12Musselshell County, MTMT5,58251.3+19%

13Golden Valley County, MTMT84450.9+23%

14Carbon County, MTMT11,46650.4+20%

15Mineral County, MTMT5,18550.0+22%

16Deer Lodge County, MTMT9,70949.9+18%

17Ravalli County, MTMT48,58248.7+18%

18Powder River County, MTMT1,78147.3+12%

19Jefferson County, MTMT13,32947.1+17%

20Sweet Grass County, MTMT3,76247.0+14%

21Stillwater County, MTMT9,44546.7+14%

22Wheatland County, MTMT2,10046.2+12%

23Judith Basin County, MTMT2,16246.2+10%

24Park County, MTMT18,21446.0+13%

25Broadwater County, MTMT8,49345.9+11%

26Powell County, MTMT7,15745.8+15%

27Phillips County, MTMT4,20345.6+12%

28Fergus County, MTMT11,82544.4+5%

29Lake County, MTMT33,39244.3+16%

30Valley County, MTMT7,38544.3+6%

31Garfield County, MTMT1,14843.3+4%

32Beaverhead County, MTMT10,04343.2+15%

33Sheridan County, MTMT3,43643.1−4%

34Chouteau County, MTMT5,86543.0+9%

35Dawson County, MTMT8,69243.0+5%

36Custer County, MTMT12,03442.7+9%

37Teton County, MTMT6,49642.3+6%

38Flathead County, MTMT115,42942.2+8%

39Pondera County, MTMT6,07242.0+9%

40Lewis and Clark County, MTMT75,33141.8+10%

41Wibaux County, MTMT88541.0−3%

42Silver Bow County, MTMT36,11840.5+4%

43Liberty County, MTMT1,95739.8−4%

44Yellowstone County, MTMT172,69239.0+6%

45Cascade County, MTMT85,02938.6+5%

46Richland County, MTMT11,37738.4−2%

47Rosebud County, MTMT8,25338.0+10%

48Toole County, MTMT5,21137.7−4%

49Fallon County, MTMT2,95937.5−9%

50Missoula County, MTMT123,51337.1+12%

51Blaine County, MTMT6,86035.6+3%

52Hill County, MTMT16,16734.5+0%

53Gallatin County, MTMT128,74034.2+11%

54Glacier County, MTMT13,46333.4+9%

55Big Horn County, MTMT12,75231.9+7%

56Roosevelt County, MTMT10,24230.9−4%

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU ACS 5-YEAR ESTIMATES