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. The median across all 56 is 44.4. Biggest climber in the top 100 since 2020: Carter County, MT, up 32 places to #3.

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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

01▲3Meagher County, MTMT2,13758.3+36%

02▲6Prairie County, MTMT1,11257.8+18%

03▲32Carter County, MTMT1,38356.9+36%

04▼3Sanders County, MTMT14,06254.6+24%

05▲21Daniels County, MTMT1,61253.4+14%

06▲17McCone County, MTMT1,72053.2+25%

07▲2Granite County, MTMT3,65853.0+24%

08▼6Lincoln County, MTMT22,32852.8+25%

09▼3Madison County, MTMT10,02652.2+20%

10▲19Treasure County, MTMT72852.0+24%

11▼8Petroleum County, MTMT54851.6+26%

12▼1Musselshell County, MTMT5,58251.3+19%

13▼8Golden Valley County, MTMT84450.9+23%

14Carbon County, MTMT11,46650.4+20%

15▼8Mineral County, MTMT5,18550.0+22%

16▼1Deer Lodge County, MTMT9,70949.9+18%

17▼4Ravalli County, MTMT48,58248.7+18%

18▼6Powder River County, MTMT1,78147.3+12%

19▼3Jefferson County, MTMT13,32947.1+17%

20▼2Sweet Grass County, MTMT3,76247.0+14%

21▼4Stillwater County, MTMT9,44546.7+14%

22▼1Wheatland County, MTMT2,10046.2+12%

23▼13Judith Basin County, MTMT2,16246.2+10%

24▼2Park County, MTMT18,21446.0+13%

25▲2Broadwater County, MTMT8,49345.9+11%

26▼1Powell County, MTMT7,15745.8+15%

27▲5Phillips County, MTMT4,20345.6+12%

28▼8Fergus County, MTMT11,82544.4+5%

29▲2Lake County, MTMT33,39244.3+16%

30▲3Valley County, MTMT7,38544.3+6%

31▼1Garfield County, MTMT1,14843.3+4%

32▲2Beaverhead County, MTMT10,04343.2+15%

33▼9Sheridan County, MTMT3,43643.1−4%

34▲10Chouteau County, MTMT5,86543.0+9%

35▲5Dawson County, MTMT8,69243.0+5%

36▲6Custer County, MTMT12,03442.7+9%

37▼9Teton County, MTMT6,49642.3+6%

38▼2Flathead County, MTMT115,42942.2+8%

39▼2Pondera County, MTMT6,07242.0+9%

40▲1Lewis and Clark County, MTMT75,33141.8+10%

41▼22Wibaux County, MTMT88541.0−3%

42▼3Silver Bow County, MTMT36,11840.5+4%

43▼5Liberty County, MTMT1,95739.8−4%

44▲4Yellowstone County, MTMT172,69239.0+6%

45▲2Cascade County, MTMT85,02938.6+5%

46▲3Richland County, MTMT11,37738.4−2%

47▼2Rosebud County, MTMT8,25338.0+10%

48▼5Toole County, MTMT5,21137.7−4%

49▼3Fallon County, MTMT2,95937.5−9%

50Missoula County, MTMT123,51337.1+12%

51▲1Blaine County, MTMT6,86035.6+3%

52▼1Hill County, MTMT16,16734.50%

53Gallatin County, MTMT128,74034.2+11%

54▲1Glacier County, MTMT13,46333.4+9%

55▲1Big Horn County, MTMT12,75231.9+7%

56▼2Roosevelt County, MTMT10,24230.9−4%

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UPDATED 2026-09-11 · DATA: US CENSUS BUREAU ACS 5-YEAR ESTIMATES