RANKING · 1990 CENSUS · 56 SHOWN OF 56

Youngest by median age, Montana counties · 1990

Montana counties with the youngest median age (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

RELATEDOldest 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

01Big Horn County, MTMT12,75228.1−6%

02Glacier County, MTMT13,46328.8−6%

03Rosebud County, MTMT8,25329.6−14%

04Gallatin County, MTMT128,74029.9−3%

05Roosevelt County, MTMT10,24230.1−7%

06Blaine County, MTMT6,86031.6−8%

07Missoula County, MTMT123,51331.7−5%

08Beaverhead County, MTMT10,04331.9−15%

09Hill County, MTMT16,16732.0−7%

10Cascade County, MTMT85,02932.8−11%

11Richland County, MTMT11,37733.2−15%

12Yellowstone County, MTMT172,69233.5−9%

13Pondera County, MTMT6,07234.0−12%

14Lewis and Clark County, MTMT75,33134.0−11%

15Phillips County, MTMT4,20334.0−17%

16Liberty County, MTMT1,95734.1−18%

17Lake County, MTMT33,39234.7−9%

18Jefferson County, MTMT13,32935.1−13%

19Fallon County, MTMT2,95935.2−14%

20Flathead County, MTMT115,42935.3−10%

21Lincoln County, MTMT22,32835.3−16%

22Toole County, MTMT5,21135.3−10%

23Custer County, MTMT12,03435.4−10%

24Garfield County, MTMT1,14835.6−15%

25Dawson County, MTMT8,69235.6−13%

26Petroleum County, MTMT54835.8−13%

27McCone County, MTMT1,72035.9−15%

28Mineral County, MTMT5,18535.9−13%

29Silver Bow County, MTMT36,11836.0−8%

30Treasure County, MTMT72836.3−13%

31Powell County, MTMT7,15736.4−8%

32Teton County, MTMT6,49636.4−9%

33Broadwater County, MTMT8,49336.6−11%

34Stillwater County, MTMT9,44536.6−10%

35Sanders County, MTMT14,06236.7−17%

36Chouteau County, MTMT5,86536.7−7%

37Valley County, MTMT7,38536.7−12%

38Powder River County, MTMT1,78136.7−13%

39Golden Valley County, MTMT84436.9−11%

40Park County, MTMT18,21437.0−9%

41Wibaux County, MTMT88537.0−13%

42Fergus County, MTMT11,82537.6−11%

43Meagher County, MTMT2,13737.6−12%

44Carter County, MTMT1,38337.8−10%

45Ravalli County, MTMT48,58237.8−8%

46Madison County, MTMT10,02637.8−13%

47Deer Lodge County, MTMT9,70938.2−10%

48Wheatland County, MTMT2,10038.6−7%

49Judith Basin County, MTMT2,16238.6−8%

50Carbon County, MTMT11,46639.1−7%

51Granite County, MTMT3,65839.3−8%

52Musselshell County, MTMT5,58239.4−9%

53Sweet Grass County, MTMT3,76239.5−4%

54Sheridan County, MTMT3,43639.6−12%

55Daniels County, MTMT1,61241.3−12%

56Prairie County, MTMT1,11243.3−11%

SHOWING 1–56 OF 56

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