RANKING · 1990 CENSUS · 44 SHOWN OF 44

Youngest by median age, Idaho counties · 1990

Idaho counties with the youngest median age (1990 ACS). This list covers the 44 counties in Idaho that qualify, ranked against each other statewide. The median across all 44 is 33.2.

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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 –

01Madison County, IDID55,17220.0–

02Jefferson County, IDID35,29726.4–

03Latah County, IDID41,84227.5–

04Franklin County, IDID15,88927.8–

05Elmore County, IDID29,46527.9–

06Bingham County, IDID51,15328.1–

07Fremont County, IDID14,20828.3–

08Bonneville County, IDID135,77128.8–

09Cassia County, IDID26,39729.0–

10Bannock County, IDID91,59129.7–

11Power County, IDID8,24630.0–

12Minidoka County, IDID22,91130.3–

13Caribou County, IDID7,25230.6–

14Teton County, IDID13,25430.6–

15Owyhee County, IDID12,66130.8–

16Oneida County, IDID5,08531.0–

17Bear Lake County, IDID6,72731.2–

18Canyon County, IDID275,12331.5–

19Ada County, IDID546,14131.9–

20Jerome County, IDID26,36232.7–

21Clark County, IDID78332.7–

22Boundary County, IDID13,99732.7–

23Twin Falls County, IDID97,53933.2–

24Butte County, IDID2,78333.3–

25Blaine County, IDID25,51733.4–

26Payette County, IDID27,82434.3–

27Benewah County, IDID10,50834.7–

28Custer County, IDID4,63634.7–

29Gooding County, IDID16,44634.9–

30Kootenai County, IDID191,86435.0–

31Lincoln County, IDID5,60335.0–

32Nez Perce County, IDID42,90535.5–

33Boise County, IDID8,54535.8–

34Gem County, IDID21,77336.1–

35Adams County, IDID5,01336.1–

36Lewis County, IDID3,70436.5–

37Idaho County, IDID17,87436.5–

38Camas County, IDID1,31636.7–

39Bonner County, IDID54,42036.8–

40Washington County, IDID11,58337.0–

41Shoshone County, IDID14,13037.2–

42Valley County, IDID12,83137.2–

43Clearwater County, IDID9,11837.8–

44Lemhi County, IDID8,47438.1–

SHOWING 1–44 OF 44

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UPDATED 2026-09-11 · DATA: US CENSUS BUREAU DECENNIAL CENSUS