RANKING · 1990 CENSUS · 56 SHOWN OF 56

Largest by population, Montana counties · 1990

The most populous Montana counties as of the 1990 population estimates. This list covers the 56 counties in Montana that qualify, ranked against each other statewide. The median across all 56 is 6,620.

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SAME RANKING BYCities States Metros ZIP codes

YEAR1990 2000 2010 2020 2025

RANKPLACESTATETOTAL POPULATIONVS –

01Yellowstone County, MTMT113,419–

02Missoula County, MTMT78,687–

03Cascade County, MTMT77,691–

04Flathead County, MTMT59,218–

05Gallatin County, MTMT50,463–

06Lewis and Clark County, MTMT47,495–

07Silver Bow County, MTMT33,941–

08Ravalli County, MTMT25,010–

09Lake County, MTMT21,041–

10Hill County, MTMT17,654–

11Lincoln County, MTMT17,481–

12Park County, MTMT14,562–

13Glacier County, MTMT12,121–

14Fergus County, MTMT12,083–

15Custer County, MTMT11,697–

16Big Horn County, MTMT11,337–

17Roosevelt County, MTMT10,999–

18Richland County, MTMT10,716–

19Rosebud County, MTMT10,505–

20Deer Lodge County, MTMT10,278–

21Dawson County, MTMT9,505–

22Sanders County, MTMT8,669–

23Beaverhead County, MTMT8,424–

24Valley County, MTMT8,239–

25Carbon County, MTMT8,080–

26Jefferson County, MTMT7,939–

27Blaine County, MTMT6,728–

28Powell County, MTMT6,620–

29Stillwater County, MTMT6,536–

30Pondera County, MTMT6,433–

31Teton County, MTMT6,271–

32Madison County, MTMT5,989–

33Chouteau County, MTMT5,452–

34Phillips County, MTMT5,163–

35Toole County, MTMT5,046–

36Sheridan County, MTMT4,732–

37Musselshell County, MTMT4,106–

38Broadwater County, MTMT3,318–

39Mineral County, MTMT3,315–

40Sweet Grass County, MTMT3,154–

41Fallon County, MTMT3,103–

42Granite County, MTMT2,548–

43Liberty County, MTMT2,295–

44Judith Basin County, MTMT2,282–

45McCone County, MTMT2,276–

46Daniels County, MTMT2,266–

47Wheatland County, MTMT2,246–

48Powder River County, MTMT2,090–

49Meagher County, MTMT1,819–

50Garfield County, MTMT1,589–

51Carter County, MTMT1,503–

52Prairie County, MTMT1,383–

53Wibaux County, MTMT1,191–

54Golden Valley County, MTMT912–

55Treasure County, MTMT874–

56Petroleum County, MTMT519–

SHOWING 1–56 OF 56

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