RANKING · 2020 CENSUS · 44 SHOWN OF 44

Fastest growing, Idaho counties · 2020

Idaho counties ranked by population growth from the 2010 census to 2020. This list covers the 44 counties in Idaho that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

RELATEDLargest by population Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Madison County, IDID55,172+41.0%+24.9 pts

02Ada County, IDID546,141+26.1%−20.1 pts

03Kootenai County, IDID191,864+23.7%−32.0 pts

04Canyon County, IDID275,123+22.3%−23.6 pts

05Valley County, IDID12,831+19.1%−6.1 pts

06Bonneville County, IDID135,771+18.9%+4.6 pts

07Jefferson County, IDID35,297+18.2%+2.4 pts

08Twin Falls County, IDID97,539+16.6%−3.4 pts

09Bonner County, IDID54,420+15.2%−23.1 pts

10Gem County, IDID21,773+14.4%−13.8 pts

11Teton County, IDID13,254+14.4%−60.1 pts

12Blaine County, IDID25,517+13.5%−26.6 pts

13Payette County, IDID27,824+12.2%−13.0 pts

14Franklin County, IDID15,889+11.0%−11.7 pts

15Adams County, IDID5,013+10.1%+3.3 pts

16Boundary County, IDID13,997+9.9%−8.6 pts

17Jerome County, IDID26,362+8.3%−12.8 pts

18Boise County, IDID8,545+8.3%−81.8 pts

19Minidoka County, IDID22,911+7.7%+3.5 pts

20Cassia County, IDID26,397+7.4%−2.2 pts

21Nez Perce County, IDID42,905+7.2%−3.6 pts

22Oneida County, IDID5,085+6.5%−11.6 pts

23Bear Lake County, IDID6,727+6.4%+1.1 pts

24Latah County, IDID41,842+6.1%−8.0 pts

25Elmore County, IDID29,465+6.0%−31.4 pts

26Bingham County, IDID51,153+5.2%−5.8 pts

27Bannock County, IDID91,591+5.0%−9.4 pts

28Owyhee County, IDID12,661+3.4%−23.5 pts

29Shoshone County, IDID14,130+3.2%+4.3 pts

30Washington County, IDID11,583+3.0%−13.7 pts

31Benewah County, IDID10,508+2.6%−12.9 pts

32Idaho County, IDID17,874+1.7%−10.9 pts

33Fremont County, IDID14,208+1.1%−7.0 pts

34Caribou County, IDID7,252+0.9%−4.0 pts

35Gooding County, IDID16,446+0.9%−20.8 pts

36Power County, IDID8,246+0.8%−5.6 pts

37Lemhi County, IDID8,474+0.5%−12.7 pts

38Clearwater County, IDID9,118-0.3%−5.3 pts

39Lincoln County, IDID5,603-1.6%−23.8 pts

40Custer County, IDID4,636-2.1%−7.2 pts

41Camas County, IDID1,316-3.6%−39.9 pts

42Lewis County, IDID3,704-7.5%−14.1 pts

43Butte County, IDID2,783-11.0%−10.3 pts

44Clark County, IDID783-19.6%−53.7 pts

SHOWING 1–44 OF 44

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UPDATED 2026-08-08 · DATA: US CENSUS BUREAU DECENNIAL CENSUS