RANKING · 2000 CENSUS · 56 SHOWN OF 56

Most population gained, Montana counties · 2000

Montana counties that added the most residents from the 1990 census to 2000, by raw count of people rather than percentage. This list covers the 56 counties in Montana that qualify, ranked against each other statewide. The median across all 56 is +221.

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SAME RANKING BYCities States Metros

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

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION CHANGEVS –

01Gallatin County, MTMT128,740+17,368–

02Missoula County, MTMT123,513+17,115–

03Yellowstone County, MTMT172,692+15,933–

04Flathead County, MTMT115,429+15,253–

05Ravalli County, MTMT48,582+11,060–

06Lewis and Clark County, MTMT75,331+8,221–

07Lake County, MTMT33,392+5,466–

08Cascade County, MTMT85,029+2,666–

09Jefferson County, MTMT13,329+2,110–

10Stillwater County, MTMT9,445+1,659–

11Sanders County, MTMT14,062+1,558–

12Carbon County, MTMT11,466+1,472–

13Lincoln County, MTMT22,328+1,356–

14Big Horn County, MTMT12,752+1,334–

15Park County, MTMT18,214+1,132–

16Glacier County, MTMT13,463+1,126–

17Broadwater County, MTMT8,493+1,067–

18Madison County, MTMT10,026+862–

19Beaverhead County, MTMT10,043+778–

20Silver Bow County, MTMT36,118+665–

21Mineral County, MTMT5,185+569–

22Powell County, MTMT7,157+560–

23Chouteau County, MTMT5,865+518–

24Sweet Grass County, MTMT3,762+455–

25Musselshell County, MTMT5,582+391–

26Granite County, MTMT3,658+282–

27Blaine County, MTMT6,860+281–

28Toole County, MTMT5,211+221–

29Teton County, MTMT6,496+174–

30Golden Valley County, MTMT844+130–

31Meagher County, MTMT2,137+113–

32Judith Basin County, MTMT2,162+47–

33Wheatland County, MTMT2,100+13–

34Custer County, MTMT12,034-1–

35Pondera County, MTMT6,072-9–

36Treasure County, MTMT728-13–

37Petroleum County, MTMT548-26–

38Wibaux County, MTMT885-123–

39Liberty County, MTMT1,957-137–

40Carter County, MTMT1,383-143–

41Prairie County, MTMT1,112-184–

42Fergus County, MTMT11,825-190–

43Powder River County, MTMT1,781-232–

44Daniels County, MTMT1,612-249–

45Fallon County, MTMT2,959-266–

46McCone County, MTMT1,720-299–

47Garfield County, MTMT1,148-310–

48Roosevelt County, MTMT10,242-379–

49Dawson County, MTMT8,692-446–

50Phillips County, MTMT4,203-562–

51Valley County, MTMT7,385-564–

52Sheridan County, MTMT3,436-627–

53Deer Lodge County, MTMT9,709-861–

54Hill County, MTMT16,167-981–

55Richland County, MTMT11,377-1,049–

56Rosebud County, MTMT8,253-1,122–

SHOWING 1–56 OF 56

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