RANKING · 2020 CENSUS · 44 SHOWN OF 44

Most population gained, Idaho counties · 2020

Idaho counties that added the most residents from the 2010 census to 2020, by raw count of people rather than percentage. This list covers the 44 counties in Idaho that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION CHANGEVS 2000

01Ada County, IDID546,141+102,602+8%

02Canyon County, IDID275,123+42,182+2%

03Kootenai County, IDID191,864+32,868−15%

04Bonneville County, IDID135,771+19,730+91%

05Madison County, IDID55,172+15,377+305%

06Twin Falls County, IDID97,539+12,816+20%

07Bonner County, IDID54,420+6,233−39%

08Jefferson County, IDID35,297+4,751+82%

09Bannock County, IDID91,591+4,179−56%

10Blaine County, IDID25,517+2,896−47%

11Nez Perce County, IDID42,905+2,825−23%

12Payette County, IDID27,824+2,763−33%

13Gem County, IDID21,773+2,404−28%

14Bingham County, IDID51,153+2,385−43%

15Latah County, IDID41,842+2,273−47%

16Valley County, IDID12,831+1,884+22%

17Jerome County, IDID26,362+1,863−42%

18Cassia County, IDID26,397+1,703−10%

19Elmore County, IDID29,465+1,628−79%

20Minidoka County, IDID22,911+1,544+90%

21Teton County, IDID13,254+1,460−43%

22Franklin County, IDID15,889+1,408−33%

23Boundary County, IDID13,997+1,084−30%

24Boise County, IDID8,545+582−82%

25Shoshone County, IDID14,130+404−353%

26Adams County, IDID5,013+403+82%

27Owyhee County, IDID12,661+387−83%

28Bear Lake County, IDID6,727+386+18%

29Washington County, IDID11,583+302−79%

30Oneida County, IDID5,085+278−56%

31Idaho County, IDID17,874+274−84%

32Benewah County, IDID10,508+245−80%

33Fremont County, IDID14,208+146−83%

34Gooding County, IDID16,446+134−95%

35Caribou County, IDID7,252+64−81%

36Power County, IDID8,246+61−87%

37Lemhi County, IDID8,474+38−96%

38Clearwater County, IDID9,118-27−106%

39Camas County, IDID1,316-40−115%

40Lincoln County, IDID5,603-81−111%

41Custer County, IDID4,636-93−144%

42Clark County, IDID783-192−174%

43Lewis County, IDID3,704-288−225%

44Butte County, IDID2,783-317+1568%

SHOWING 1–44 OF 44

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