RANKING · 2000 CENSUS · 56 SHOWN OF 56

Largest by population, Montana counties · 2000

The most populous Montana counties as of the 2000 population estimates. This list covers the 56 counties in Montana that qualify, ranked against each other statewide.

MontanaAll states All rankings

SAME RANKING BYCities States Metros ZIP codes

RELATEDFastest growing Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR1990 2000 2010 2020 2025

RANKPLACESTATETOTAL POPULATIONVS 1990

01Yellowstone County, MTMT129,352+14%

02Missoula County, MTMT95,802+22%

03Cascade County, MTMT80,357+3%

04Flathead County, MTMT74,471+26%

05Gallatin County, MTMT67,831+34%

06Lewis and Clark County, MTMT55,716+17%

07Ravalli County, MTMT36,070+44%

08Silver Bow County, MTMT34,606+2%

09Lake County, MTMT26,507+26%

10Lincoln County, MTMT18,837+8%

11Hill County, MTMT16,673−6%

12Park County, MTMT15,694+8%

13Glacier County, MTMT13,247+9%

14Big Horn County, MTMT12,671+12%

15Fergus County, MTMT11,893−2%

16Custer County, MTMT11,696−0%

17Roosevelt County, MTMT10,620−3%

18Sanders County, MTMT10,227+18%

19Jefferson County, MTMT10,049+27%

20Richland County, MTMT9,667−10%

21Carbon County, MTMT9,552+18%

22Deer Lodge County, MTMT9,417−8%

23Rosebud County, MTMT9,383−11%

24Beaverhead County, MTMT9,202+9%

25Dawson County, MTMT9,059−5%

26Stillwater County, MTMT8,195+25%

27Valley County, MTMT7,675−7%

28Powell County, MTMT7,180+8%

29Blaine County, MTMT7,009+4%

30Madison County, MTMT6,851+14%

31Teton County, MTMT6,445+3%

32Pondera County, MTMT6,424−0%

33Chouteau County, MTMT5,970+10%

34Toole County, MTMT5,267+4%

35Phillips County, MTMT4,601−11%

36Musselshell County, MTMT4,497+10%

37Broadwater County, MTMT4,385+32%

38Sheridan County, MTMT4,105−13%

39Mineral County, MTMT3,884+17%

40Sweet Grass County, MTMT3,609+14%

41Fallon County, MTMT2,837−9%

42Granite County, MTMT2,830+11%

43Judith Basin County, MTMT2,329+2%

44Wheatland County, MTMT2,259+1%

45Liberty County, MTMT2,158−6%

46Daniels County, MTMT2,017−11%

47McCone County, MTMT1,977−13%

48Meagher County, MTMT1,932+6%

49Powder River County, MTMT1,858−11%

50Carter County, MTMT1,360−10%

51Garfield County, MTMT1,279−20%

52Prairie County, MTMT1,199−13%

53Wibaux County, MTMT1,068−10%

54Golden Valley County, MTMT1,042+14%

55Treasure County, MTMT861−1%

56Petroleum County, MTMT493−5%

SHOWING 1–56 OF 56

Download CSV (full list, 56 rows)

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