RANKING · 1990 CENSUS · 44 SHOWN OF 44

Youngest by median age, Idaho counties · 1990

Idaho counties with the youngest median age (2023 ACS). This list covers the 44 counties in Idaho 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

01Madison County, IDID55,17220.0−4%

02Jefferson County, IDID35,29726.4−8%

03Latah County, IDID41,84227.5−2%

04Franklin County, IDID15,88927.8+0%

05Elmore County, IDID29,46527.9−4%

06Bingham County, IDID51,15328.1−5%

07Fremont County, IDID14,20828.3−11%

08Bonneville County, IDID135,77128.8−9%

09Cassia County, IDID26,39729.0−7%

10Bannock County, IDID91,59129.7−0%

11Power County, IDID8,24630.0−5%

12Minidoka County, IDID22,91130.3−10%

13Caribou County, IDID7,25230.6−13%

14Teton County, IDID13,25430.6−2%

15Owyhee County, IDID12,66130.8−6%

16Oneida County, IDID5,08531.0−14%

17Bear Lake County, IDID6,72731.2−13%

18Canyon County, IDID275,12331.5+3%

19Ada County, IDID546,14131.9−3%

20Jerome County, IDID26,36232.7−1%

21Clark County, IDID78332.7+7%

22Boundary County, IDID13,99732.7−15%

23Twin Falls County, IDID97,53933.2−5%

24Butte County, IDID2,78333.3−14%

25Blaine County, IDID25,51733.4−11%

26Payette County, IDID27,82434.3−0%

27Benewah County, IDID10,50834.7−11%

28Custer County, IDID4,63634.7−16%

29Gooding County, IDID16,44634.9−1%

30Kootenai County, IDID191,86435.0−3%

31Lincoln County, IDID5,60335.0+2%

32Nez Perce County, IDID42,90535.5−7%

33Boise County, IDID8,54535.8−12%

34Gem County, IDID21,77336.1−4%

35Adams County, IDID5,01336.1−19%

36Lewis County, IDID3,70436.5−14%

37Idaho County, IDID17,87436.5−14%

38Camas County, IDID1,31636.7−8%

39Bonner County, IDID54,42036.8−10%

40Washington County, IDID11,58337.0−6%

41Shoshone County, IDID14,13037.2−11%

42Valley County, IDID12,83137.2−15%

43Clearwater County, IDID9,11837.8−9%

44Lemhi County, IDID8,47438.1−11%

SHOWING 1–44 OF 44

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