Population Of Colorado-

3 307,618 (1990)
4,327,788 (2000)
5,024,748 (2009)

Most Populated Cities-

1. El Poso- 622,073
2. Jefferson- 595,821
3. Denver- 581,224
4. Arapahoe- 438,816
5. Adams- 438,816
6. Larimer- 298,982
7. Douglas- 285,061
8. Boulder- 277,353
9. La Plata- 49,307
10. Fremont- 40,041
11. Montrose- 37,639
12. Morgan- 28,040
13. Delta-26,892
14. Teller- 20,840
15. Montezuma- 20,039
16. Otero- 18,647
17. Logan- 17,821
18. Alamosa- 15,112
19. Eagle- 14,945
20. Las Animas- 14,133
21. Chaffee- 13,920
22. Rio Grande- 13,733
23. Elbert- 13,316 
24. Moffat- 12,769
25. Gunnison- 11,683
26. Pitkin- 10,767

El Poso

Denver

Least Populated Cities-

27. Prowers- 10,486
28. Routt- 9,775
29. Park- 9,775
30. Yuma- 9,444
31. Archuleta- 8,348
32. Kit Carson- 6,061
33. Washington- 3,849
34. Conejos- 3,278
35. Custer- 2,825
36. Gilpin- 2,628
37. Baca- 2,494
38. San Miguel- 2,429
39. Crowley- 2,425
40. Ouray- 2,326
41. Sedgwick- 1,886
42. Lincoln- 1,841
43. Costilla- 1,320
44. Clear Creek- 1,076
45. Grand- 1,066
46. Kiowa- 780
47. Saguache- 751
48. Mineral- 645
49. Cheyenne- 447
50. Jackson- 421
51. Dolores- 274
52. Hinsdale- 7

Hinsdale