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%−19%

03Douglas County, COCO399,396+25.4%−87%

04Mineral County, COCO910+21.5%−56%

05Larimer County, COCO377,292+19.8%−44%

06Denver County, COCO740,613+19.2%+3%

07Adams County, COCO554,668+17.7%−53%

08El Paso County, COCO757,040+17.4%−42%

09Arapahoe County, COCO673,820+14.5%−41%

10Elbert County, COCO30,534+12.9%−88%

11Dolores County, COCO2,466+12.7%−44%

12Boulder County, COCO328,560+12.3%−58%

13Summit County, COCO31,517+10.9%−87%

14Custer County, COCO5,590+10.6%−87%

15Archuleta County, COCO14,306+10.6%−88%

16Gunnison County, COCO17,439+10.4%−71%

17Ouray County, COCO5,265+9.9%−84%

18San Miguel County, COCO7,753+9.7%−88%

19Garfield County, COCO63,474+9.4%−80%

20Chaffee County, COCO20,831+9.4%−67%

21Jefferson County, COCO580,451+9.0%−55%

22La Plata County, COCO56,898+8.4%−77%

23Park County, COCO18,314+7.3%−93%

24Eagle County, COCO54,291+6.8%−92%

25Gilpin County, COCO6,073+6.7%−88%

26Mesa County, COCO162,845+6.1%−75%

27Alamosa County, COCO16,688+6.0%−39%

28Grand County, COCO16,496+5.9%−90%

29Teller County, COCO24,756+5.8%−91%

30Pueblo County, COCO169,277+5.7%−62%

31Routt County, COCO25,329+5.6%−86%

32Fremont County, COCO50,039+4.5%−89%

33Saguache County, COCO6,732+4.3%−85%

34Lincoln County, COCO5,645+3.8%−89%

35Kiowa County, COCO1,412+3.4%−188%

36Clear Creek County, COCO8,994+3.4%−85%

37Montrose County, COCO44,591+3.4%−91%

38Morgan County, COCO30,306+3.4%−86%

39Phillips County, COCO4,420+2.0%−71%

40Lake County, COCO7,552+1.7%−94%

41Crowley County, COCO5,677+1.7%−96%

42Huerfano County, COCO7,011+1.6%−95%

43Montezuma County, COCO26,678+1.2%−96%

44Pitkin County, COCO16,625+1.2%−93%

45Sedgwick County, COCO2,247+1.1%−50%

46San Juan County, COCO813+0.9%−103%

47Delta County, COCO32,178+0.8%−98%

48Washington County, COCO4,732+0.1%−97%

49Yuma County, COCO9,896-0.5%−106%

50Costilla County, COCO3,679-0.7%−105%

51Otero County, COCO17,683-0.7%−220%

52Jackson County, COCO1,211-1.1%−38%

53Rio Blanco County, COCO6,683-2.1%−977%

54Moffat County, COCO13,122-3.6%−123%

55Rio Grande County, COCO11,087-3.7%−124%

56Prowers County, COCO11,884-4.4%−152%

57Cheyenne County, COCO1,713-4.8%−31%

58Logan County, COCO20,654-5.2%−131%

59Las Animas County, COCO14,391-6.1%−159%

60Hinsdale County, COCO753-6.5%−109%

61Baca County, COCO3,347-7.4%+770%

62Conejos County, COCO7,529-9.6%−176%

63Bent County, COCO5,716-13.1%−169%

64Kit Carson County, COCO7,069-14.3%−217%

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