RANKING · 2025 ESTIMATES · 44 SHOWN OF 44

Most population gained, Idaho counties

Idaho counties that added the most residents from the 2020 census to 2025, 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+51,174−46%

02Canyon County, IDID275,123+44,018+6%

03Kootenai County, IDID191,864+20,502−47%

04Bonneville County, IDID135,771+11,807+14%

05Twin Falls County, IDID97,539+7,493−30%

06Bonner County, IDID54,420+7,310−28%

07Bannock County, IDID91,591+4,573−52%

08Jefferson County, IDID35,297+4,406+69%

09Bingham County, IDID51,153+3,161−24%

10Gem County, IDID21,773+2,650−21%

11Payette County, IDID27,824+2,438−41%

12Latah County, IDID41,842+2,325−46%

13Madison County, IDID55,172+2,259−40%

14Jerome County, IDID26,362+2,125−34%

15Boundary County, IDID13,997+1,941+26%

16Cassia County, IDID26,397+1,742−8%

17Franklin County, IDID15,889+1,695−19%

18Teton County, IDID13,254+1,624−37%

19Idaho County, IDID17,874+1,333−23%

20Minidoka County, IDID22,911+1,298+60%

21Blaine County, IDID25,517+1,245−77%

22Valley County, IDID12,831+1,085−30%

23Washington County, IDID11,583+1,083−24%

24Benewah County, IDID10,508+978−21%

25Shoshone County, IDID14,130+961−701%

26Boise County, IDID8,545+935−70%

27Gooding County, IDID16,446+848−66%

28Fremont County, IDID14,208+820−7%

29Nez Perce County, IDID42,905+815−78%

30Elmore County, IDID29,465+799−90%

31Owyhee County, IDID12,661+748−67%

32Adams County, IDID5,013+634+186%

33Oneida County, IDID5,085+521−18%

34Lemhi County, IDID8,474+500−45%

35Lincoln County, IDID5,603+476−35%

36Clearwater County, IDID9,118+384−10%

37Power County, IDID8,246+368−19%

38Custer County, IDID4,636+361+73%

39Bear Lake County, IDID6,727+355+9%

40Camas County, IDID1,316+239−9%

41Caribou County, IDID7,252+225−34%

42Butte County, IDID2,783+209−1200%

43Lewis County, IDID3,704+171−26%

44Clark County, IDID783-7−103%

SHOWING 1–44 OF 44

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU POPULATION ESTIMATES