RANKING · 2025 ESTIMATES · 44 SHOWN OF 44

Most sparsely populated, Idaho counties

Idaho counties with the fewest residents per square mile (2025). This list covers the 44 counties in Idaho that qualify, ranked against each other statewide. The median across all 44 is 10.

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SAME RANKING BYCities States Metros

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

YEAR1990 2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION DENSITYVS 2000

01Clark County, IDID7830−23%

02Custer County, IDID4,6361+7%

03Camas County, IDID1,3161+33%

04Butte County, IDID2,7831−4%

05Owyhee County, IDID12,6612+19%

06Lemhi County, IDID8,4742+9%

07Idaho County, IDID17,8742+15%

08Valley County, IDID12,8314+68%

09Adams County, IDID5,0134+44%

10Clearwater County, IDID9,1184+2%

11▲1Caribou County, IDID7,2524−1%

12▼1Oneida County, IDID5,0854+23%

13Boise County, IDID8,5454+28%

14Lincoln County, IDID5,6035+39%

15Shoshone County, IDID14,1305+3%

16Power County, IDID8,2466+9%

17Bear Lake County, IDID6,7277+5%

18Fremont County, IDID14,2088+20%

19▲1Lewis County, IDID3,7048−1%

20▼1Washington County, IDID11,5838+16%

21▲1Elmore County, IDID29,46510+1%

22▼1Blaine County, IDID25,51710+34%

23▲1Cassia County, IDID26,39710+23%

24▼1Boundary County, IDID13,99711+42%

25Benewah County, IDID10,50814+15%

26Gooding County, IDID16,44623+16%

27Franklin County, IDID15,88924+40%

28Bingham County, IDID51,15324+23%

29Teton County, IDID13,25430+121%

30▲2Minidoka County, IDID22,91130+14%

31▼1Bonner County, IDID54,42031+48%

32▼1Jefferson County, IDID35,29732+84%

33▲1Latah County, IDID41,84239+20%

34▼1Gem County, IDID21,77339+43%

35Jerome County, IDID26,36244+44%

36▲1Nez Perce County, IDID42,90551+15%

37▼1Twin Falls County, IDID97,53951+52%

38Payette County, IDID27,82468+35%

39Bonneville County, IDID135,77173+65%

40Bannock County, IDID91,59182+21%

41Madison County, IDID55,172118+101%

42Kootenai County, IDID191,864155+77%

43Canyon County, IDID275,123469+109%

44Ada County, IDID546,141519+82%

SHOWING 1–44 OF 44

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UPDATED 2026-09-11 · DATA: US CENSUS BUREAU POPULATION ESTIMATES