RANKING · 2020 CENSUS · 44 SHOWN OF 44

Youngest by median age, Idaho counties · 2020

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, IDID55,17223.1+12%

02Latah County, IDID41,84231.0+11%

03Jefferson County, IDID35,29732.1+11%

04Elmore County, IDID29,46532.7+12%

05Bonneville County, IDID135,77133.1+4%

06Cassia County, IDID26,39733.1+6%

07Jerome County, IDID26,36233.4+2%

08Franklin County, IDID15,88933.9+22%

09Canyon County, IDID275,12334.5+13%

10Bannock County, IDID91,59134.7+16%

11Bingham County, IDID51,15334.8+17%

12Minidoka County, IDID22,91135.2+5%

13Power County, IDID8,24635.3+12%

14Twin Falls County, IDID97,53935.8+3%

15Lincoln County, IDID5,60336.5+6%

16Gooding County, IDID16,44637.1+6%

17Ada County, IDID546,14137.4+14%

18Caribou County, IDID7,25237.5+7%

19Fremont County, IDID14,20837.7+18%

20Teton County, IDID13,25437.7+20%

21Clark County, IDID78337.9+23%

22Owyhee County, IDID12,66138.8+18%

23Payette County, IDID27,82439.4+15%

24Bear Lake County, IDID6,72740.1+12%

25Oneida County, IDID5,08540.3+12%

26Nez Perce County, IDID42,90540.9+7%

27Kootenai County, IDID191,86441.2+14%

28Butte County, IDID2,78342.7+10%

29Gem County, IDID21,77344.1+18%

30Blaine County, IDID25,51745.4+21%

31Washington County, IDID11,58346.0+17%

32Boundary County, IDID13,99746.9+22%

33Camas County, IDID1,31647.0+18%

34Benewah County, IDID10,50847.5+21%

35Shoshone County, IDID14,13048.2+15%

36Lewis County, IDID3,70448.8+15%

37Bonner County, IDID54,42049.3+21%

38Valley County, IDID12,83149.5+14%

39Idaho County, IDID17,87451.4+22%

40Clearwater County, IDID9,11852.1+25%

41Lemhi County, IDID8,47452.6+23%

42Boise County, IDID8,54553.9+33%

43Custer County, IDID4,63654.0+31%

44Adams County, IDID5,01354.9+24%

SHOWING 1–44 OF 44

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