RANKING · 1990 CENSUS · 44 SHOWN OF 44

Largest by population, Idaho counties · 1990

The most populous Idaho counties as of the 1990 population estimates. 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

RELATEDFastest growing Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR1990 2000 2010 2020 2025

RANKPLACESTATETOTAL POPULATIONVS –

01Ada County, IDID205,775–

02Canyon County, IDID90,076–

03Bonneville County, IDID72,207–

04Kootenai County, IDID69,795–

05Bannock County, IDID66,026–

06Twin Falls County, IDID53,580–

07Bingham County, IDID37,583–

08Nez Perce County, IDID33,754–

09Latah County, IDID30,617–

10Bonner County, IDID26,622–

11Madison County, IDID23,674–

12Elmore County, IDID21,205–

13Cassia County, IDID19,532–

14Minidoka County, IDID19,361–

15Jefferson County, IDID16,543–

16Payette County, IDID16,434–

17Jerome County, IDID15,138–

18Shoshone County, IDID13,931–

19Idaho County, IDID13,783–

20Blaine County, IDID13,552–

21Gem County, IDID11,844–

22Gooding County, IDID11,633–

23Fremont County, IDID10,937–

24Franklin County, IDID9,232–

25Washington County, IDID8,550–

26Clearwater County, IDID8,505–

27Owyhee County, IDID8,392–

28Boundary County, IDID8,332–

29Benewah County, IDID7,937–

30Power County, IDID7,086–

31Caribou County, IDID6,963–

32Lemhi County, IDID6,899–

33Valley County, IDID6,109–

34Bear Lake County, IDID6,084–

35Custer County, IDID4,133–

36Lewis County, IDID3,516–

37Boise County, IDID3,509–

38Oneida County, IDID3,492–

39Teton County, IDID3,439–

40Lincoln County, IDID3,308–

41Adams County, IDID3,254–

42Butte County, IDID2,918–

43Clark County, IDID762–

44Camas County, IDID727–

SHOWING 1–44 OF 44

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU DECENNIAL CENSUS