RANKING · 2020 CENSUS · 64 SHOWN OF 64

Fastest growing, Colorado counties · 2020

Colorado counties ranked by population growth from the 2010 census to 2020. This list covers the 64 counties in Colorado that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

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

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Broomfield County, COCO79,174+32.6%–

02Weld County, COCO378,426+30.1%−7.1 pts

03Douglas County, COCO399,396+25.4%−165.6 pts

04Mineral County, COCO910+21.5%−27.4 pts

05Larimer County, COCO377,292+19.8%−15.3 pts

06Denver County, COCO740,613+19.2%+0.6 pts

07Adams County, COCO554,668+17.7%−19.6 pts

08El Paso County, COCO757,040+17.4%−12.8 pts

09Arapahoe County, COCO673,820+14.5%−10.1 pts

10Elbert County, COCO30,534+12.9%−93.1 pts

11Dolores County, COCO2,466+12.7%−9.9 pts

12Boulder County, COCO328,560+12.3%−17.0 pts

13Summit County, COCO31,517+10.9%−71.9 pts

14Custer County, COCO5,590+10.6%−71.3 pts

15Archuleta County, COCO14,306+10.6%−74.6 pts

16Gunnison County, COCO17,439+10.4%−25.4 pts

17Ouray County, COCO5,265+9.9%−53.2 pts

18San Miguel County, COCO7,753+9.7%−70.8 pts

19Garfield County, COCO63,474+9.4%−36.7 pts

20Chaffee County, COCO20,831+9.4%−18.7 pts

21Jefferson County, COCO580,451+9.0%−11.2 pts

22La Plata County, COCO56,898+8.4%−27.7 pts

23Park County, COCO18,314+7.3%−95.1 pts

24Eagle County, COCO54,291+6.8%−83.2 pts

25Gilpin County, COCO6,073+6.7%−48.2 pts

26Mesa County, COCO162,845+6.1%−18.7 pts

27Alamosa County, COCO16,688+6.0%−3.9 pts

28Grand County, COCO16,496+5.9%−50.3 pts

29Teller County, COCO24,756+5.8%−59.0 pts

30Pueblo County, COCO169,277+5.7%−9.2 pts

31Routt County, COCO25,329+5.6%−34.1 pts

32Fremont County, COCO50,039+4.5%−38.5 pts

33Saguache County, COCO6,732+4.3%−23.8 pts

34Lincoln County, COCO5,645+3.8%−30.6 pts

35Kiowa County, COCO1,412+3.4%+7.3 pts

36Clear Creek County, COCO8,994+3.4%−19.0 pts

37Montrose County, COCO44,591+3.4%−33.5 pts

38Morgan County, COCO30,306+3.4%−20.5 pts

39Phillips County, COCO4,420+2.0%−5.0 pts

40Lake County, COCO7,552+1.7%−28.3 pts

41Crowley County, COCO5,677+1.7%−38.1 pts

42Huerfano County, COCO7,011+1.6%−29.2 pts

43Montezuma County, COCO26,678+1.2%−26.4 pts

44Pitkin County, COCO16,625+1.2%−16.2 pts

45Sedgwick County, COCO2,247+1.1%−1.1 pts

46San Juan County, COCO813+0.9%+26.0 pts

47Delta County, COCO32,178+0.8%−31.9 pts

48Washington County, COCO4,732+0.1%−2.3 pts

49Yuma County, COCO9,896-0.5%−10.5 pts

50Costilla County, COCO3,679-0.7%−15.5 pts

51Otero County, COCO17,683-0.7%−1.4 pts

52Jackson County, COCO1,211-1.1%+0.7 pts

53Rio Blanco County, COCO6,683-2.1%−2.3 pts

54Moffat County, COCO13,122-3.6%−19.7 pts

55Rio Grande County, COCO11,087-3.7%−19.0 pts

56Prowers County, COCO11,884-4.4%−12.9 pts

57Cheyenne County, COCO1,713-4.8%+2.1 pts

58Logan County, COCO20,654-5.2%−21.9 pts

59Las Animas County, COCO14,391-6.1%−16.6 pts

60Hinsdale County, COCO753-6.5%−75.7 pts

61Baca County, COCO3,347-7.4%−6.6 pts

62Conejos County, COCO7,529-9.6%−22.3 pts

63Bent County, COCO5,716-13.1%−31.9 pts

64Kit Carson County, COCO7,069-14.3%−26.5 pts

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UPDATED 2026-08-08 · DATA: US CENSUS BUREAU DECENNIAL CENSUS