RANKING · 2020 CENSUS · 64 SHOWN OF 64

Most population lost, Colorado counties · 2020

Colorado counties that lost the most residents from the 2010 census to 2020, by raw count of people rather than percentage. This list covers the 64 counties in Colorado that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION CHANGEVS 2000

01Kit Carson County, COCO7,069-1,183−236%

02Logan County, COCO20,654-1,181−140%

03Las Animas County, COCO14,391-952−166%

04Bent County, COCO5,716-849−189%

05Conejos County, COCO7,529-795−184%

06Prowers County, COCO11,884-552−149%

07Moffat County, COCO13,122-503−128%

08Rio Grande County, COCO11,087-443−127%

09Baca County, COCO3,347-282+623%

10Otero County, COCO17,683-141−212%

11Rio Blanco County, COCO6,683-137−1079%

12Cheyenne County, COCO1,713-88−47%

13Hinsdale County, COCO753-55−117%

14Yuma County, COCO9,896-55−106%

15Costilla County, COCO3,679-25−105%

16Jackson County, COCO1,211-15−46%

17Washington County, COCO4,732+3−97%

18San Juan County, COCO813+6−103%

19Sedgwick County, COCO2,247+25−56%

20Kiowa County, COCO1,412+48−173%

21Phillips County, COCO4,420+88−70%

22Crowley County, COCO5,677+99−94%

23Huerfano County, COCO7,011+109−94%

24Lake County, COCO7,552+126−93%

25Mineral County, COCO910+153−44%

26Lincoln County, COCO5,645+208−87%

27Pitkin County, COCO16,625+210−91%

28Delta County, COCO32,178+244−96%

29Saguache County, COCO6,732+260−80%

30Dolores County, COCO2,466+262−23%

31Clear Creek County, COCO8,994+309−82%

32Montezuma County, COCO26,678+314−94%

33Gilpin County, COCO6,073+367−78%

34Ouray County, COCO5,265+438−70%

35Custer County, COCO5,590+449−72%

36San Miguel County, COCO7,753+713−76%

37Grand County, COCO16,496+874−80%

38Alamosa County, COCO16,688+931−31%

39Morgan County, COCO30,306+952−82%

40Park County, COCO18,314+1,184−84%

41Archuleta County, COCO14,306+1,275−72%

42Routt County, COCO25,329+1,320−76%

43Teller County, COCO24,756+1,360−83%

44Montrose County, COCO44,591+1,403−84%

45Gunnison County, COCO17,439+1,594−57%

46Chaffee County, COCO20,831+1,667−53%

47Fremont County, COCO50,039+2,115−85%

48Elbert County, COCO30,534+2,976−71%

49Summit County, COCO31,517+3,061−71%

50Eagle County, COCO54,291+3,534−82%

51La Plata County, COCO56,898+4,304−63%

52Garfield County, COCO63,474+5,296−62%

53Mesa County, COCO162,845+8,980−61%

54Pueblo County, COCO169,277+9,099−51%

55Broomfield County, COCO79,174+18,223–

56Boulder County, COCO328,560+36,191−45%

57Jefferson County, COCO580,451+48,367−45%

58Larimer County, COCO377,292+59,436−9%

59Douglas County, COCO399,396+72,513−37%

60Weld County, COCO378,426+76,156+55%

61Adams County, COCO554,668+77,969−21%

62Arapahoe County, COCO673,820+83,067−14%

63El Paso County, COCO757,040+108,132−10%

64Denver County, COCO740,613+115,364+33%

SHOWING 1–64 OF 64

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