RANKING · 1990 CENSUS · 44 SHOWN OF 44

Most densely populated, Idaho counties · 1990

Idaho counties ranked by residents per square mile (1990). This list covers the 44 counties in Idaho that qualify, ranked against each other statewide. The median across all 44 is 7.

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SAME RANKING BYCities States Metros

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

YEAR1990 2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION DENSITYVS –

01Ada County, IDID546,141196–

02Canyon County, IDID275,123153–

03Bannock County, IDID91,59159–

04Kootenai County, IDID191,86456–

05Madison County, IDID55,17250–

06Payette County, IDID27,82440–

07Nez Perce County, IDID42,90540–

08Bonneville County, IDID135,77139–

09Latah County, IDID41,84228–

10Twin Falls County, IDID97,53928–

11Minidoka County, IDID22,91126–

12Jerome County, IDID26,36225–

13Gem County, IDID21,77321–

14Bingham County, IDID51,15318–

15Gooding County, IDID16,44616–

16Bonner County, IDID54,42015–

17Jefferson County, IDID35,29715–

18Franklin County, IDID15,88914–

19Benewah County, IDID10,50810–

20Teton County, IDID13,2548–

21Cassia County, IDID26,3978–

22Lewis County, IDID3,7047–

23Elmore County, IDID29,4657–

24Boundary County, IDID13,9977–

25Bear Lake County, IDID6,7276–

26Washington County, IDID11,5836–

27Fremont County, IDID14,2086–

28Shoshone County, IDID14,1305–

29Blaine County, IDID25,5175–

30Power County, IDID8,2465–

31Caribou County, IDID7,2524–

32Clearwater County, IDID9,1183–

33Oneida County, IDID5,0853–

34Lincoln County, IDID5,6033–

35Adams County, IDID5,0132–

36Boise County, IDID8,5452–

37Valley County, IDID12,8312–

38Idaho County, IDID17,8742–

39Lemhi County, IDID8,4742–

40Butte County, IDID2,7831–

41Owyhee County, IDID12,6611–

42Custer County, IDID4,6361–

43Camas County, IDID1,3161–

44Clark County, IDID7830–

SHOWING 1–44 OF 44

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