RANKING · 2000 CENSUS · 99 SHOWN OF 99

Most densely populated, Iowa counties · 2000

Iowa counties ranked by residents per square mile (2000). This list covers the 99 counties in Iowa that qualify, ranked against each other statewide. The median across all 99 is 29.

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SAME RANKING BYCities States Metros

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

YEAR1990 2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION DENSITYVS 1990

01Polk County, IAIA516,546654+15%

02Scott County, IAIA175,259346+5%

03Linn County, IAIA232,028267+14%

04Black Hawk County, IAIA131,532226+3%

05Johnson County, IAIA160,044181+15%

06Dubuque County, IAIA99,381147+3%

07Story County, IAIA101,291140+8%

08Woodbury County, IAIA106,649119+6%

09Des Moines County, IAIA38,077102−1%

10Muscatine County, IAIA41,85395+5%

11Pottawattamie County, IAIA92,99692+6%

12Wapello County, IAIA35,21083+1%

13Cerro Gordo County, IAIA42,37282−1%

14Lee County, IAIA32,30674−2%

15Clinton County, IAIA46,00272−2%

16Warren County, IAIA57,33171+13%

17Dallas County, IAIA118,45769+37%

18Marshall County, IAIA39,89069+3%

19Marion County, IAIA34,19258+7%

20Webster County, IAIA36,838560%

21Bremer County, IAIA25,29654+2%

22Jasper County, IAIA38,15351+7%

23Henry County, IAIA19,34947+6%

24Boone County, IAIA26,79946+4%

25Dickinson County, IAIA18,07743+10%

26Sioux County, IAIA36,77441+6%

27Mahaska County, IAIA21,88039+4%

28Carroll County, IAIA20,303380%

29Jefferson County, IAIA15,29137−1%

30Buchanan County, IAIA20,88337+1%

31Washington County, IAIA22,66736+5%

32Buena Vista County, IAIA20,44936+2%

33Benton County, IAIA26,00435+13%

34Jones County, IAIA21,25335+4%

35Floyd County, IAIA14,90134−1%

36Mills County, IAIA14,79333+10%

37Hardin County, IAIA16,45533−1%

38Poweshiek County, IAIA18,36832−1%

39Jackson County, IAIA19,28832+2%

40Delaware County, IAIA17,67432+2%

41Page County, IAIA14,85632+1%

42Cedar County, IAIA18,35931+5%

43Winneshiek County, IAIA19,73331+2%

44Clay County, IAIA16,20231−1%

45Louisa County, IAIA10,41630+5%

46Fayette County, IAIA19,04730+1%

47Winnebago County, IAIA10,25129−3%

48Union County, IAIA11,82929−3%

49Plymouth County, IAIA25,69729+6%

50Hamilton County, IAIA14,94429+2%

51Emmet County, IAIA9,10728−5%

52Montgomery County, IAIA10,00228−3%

53Appanoose County, IAIA12,077280%

54Iowa County, IAIA16,50427+7%

55Butler County, IAIA14,04926−3%

56O'Brien County, IAIA14,22026−2%

57Cass County, IAIA12,96026−3%

58Chickasaw County, IAIA11,66326−2%

59Tama County, IAIA16,79625+4%

60Madison County, IAIA17,27025+12%

61Wright County, IAIA12,801250%

62Grundy County, IAIA12,36125+3%

63Clayton County, IAIA16,84524−2%

64Humboldt County, IAIA9,40924−3%

65Crawford County, IAIA16,23724+1%

66Mitchell County, IAIA10,650230%

67Allamakee County, IAIA14,23823+6%

68Cherokee County, IAIA11,36923−8%

69Harrison County, IAIA14,62322+6%

70Shelby County, IAIA11,689220%

71Lucas County, IAIA8,84722+4%

72Hancock County, IAIA10,52821−4%

73Clarke County, IAIA9,57421+10%

74Howard County, IAIA9,41521+1%

75Sac County, IAIA9,52520−6%

76Lyon County, IAIA12,35420−2%

77Worth County, IAIA7,33820−1%

78Keokuk County, IAIA9,79720−2%

79Calhoun County, IAIA9,56220−3%

80Guthrie County, IAIA10,78219+4%

81Monroe County, IAIA7,40618−1%

82Franklin County, IAIA9,86818−6%

83Greene County, IAIA8,65818+3%

84Ida County, IAIA6,77718−6%

85Palo Alto County, IAIA8,89918−5%

86Kossuth County, IAIA14,32218−8%

87Osceola County, IAIA5,98018−4%

88Davis County, IAIA9,23017+3%

89Decatur County, IAIA7,65516+4%

90Van Buren County, IAIA7,13116+2%

91Fremont County, IAIA6,52216−3%

92Audubon County, IAIA5,50915−7%

93Pocahontas County, IAIA6,81915−9%

94Adair County, IAIA7,40314−2%

95Monona County, IAIA8,539140%

96Taylor County, IAIA5,83513−2%

97Wayne County, IAIA6,73813−5%

98Adams County, IAIA3,61711−8%

99Ringgold County, IAIA4,64210+1%

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