PlainCities

Counties · Colorado

Counties of Colorado

Colorado has 64 counties. El Paso County is the largest with 757,040 residents in 2025. 40 of the 64 gained residents between 2020 and 2025 by the Census Bureau's estimates.

What counties are in Colorado?

Sorted by the 2025 population estimate; sort by any column.

Counties of Colorado: 2025 estimate, change since 2020, ACS 2020-2024 5-year estimates
El Paso County757,040+3.5%20167$90,363$461,000
Denver County740,613+3.5%1178$94,718$616,000
Arapahoe County673,820+2.9%26161$101,087$561,200
Jefferson County580,451−0.4%27146$110,656$637,600
Adams County554,668+6.8%20107$94,571$484,200
Douglas County399,396+11.6%2472$149,594$713,600
Weld County378,426+15.0%3483$97,097$471,700
Larimer County377,292+5.1%1086$93,765$569,100
Boulder County328,560−0.7%3478$103,994$756,300
Pueblo County169,277+0.7%1058$64,010$291,300
Mesa County162,845+4.6%1033$73,658$378,600
Broomfield County79,174+6.8%124$123,874$664,500
Garfield County63,474+2.9%1312$91,131$527,800
La Plata County56,898+2.3%512$86,056$591,500
Eagle County54,291−2.6%1316$104,096$839,500
Fremont County50,039+2.3%1215$62,664$324,000
Montrose County44,591+4.5%512$72,120$388,400
Delta County32,178+3.1%79$57,774$343,200
Summit County31,517+0.7%912$109,773$939,900
Elbert County30,534+17.2%67$132,685$709,800
Morgan County30,306+4.1%138$73,278$338,600
Montezuma County26,678+3.2%58$65,244$331,400
Routt County25,329+2.0%510$106,489$854,700
Teller County24,756+0.2%88$85,361$479,900
Chaffee County20,831+7.0%86$84,132$665,700
Logan County20,654−4.1%87$51,829$245,300
Park County18,314+5.3%46$103,670$532,100
Otero County17,683−5.4%87$54,037$168,900
Gunnison County17,439+3.1%66$84,527$621,800
Alamosa County16,688+1.9%35$55,397$239,100
Pitkin County16,625−4.2%66$102,645$1,139,100
Grand County16,496+5.0%86$88,612$601,500
Las Animas County14,391−1.1%146$52,074$237,600
Archuleta County14,306+7.1%25$83,065$478,100
Moffat County13,122−1.3%34$73,849$289,500
Prowers County11,884−0.9%55$53,508$160,600
Rio Grande County11,087−3.9%64$64,411$239,500
Yuma County9,896−0.9%82$60,545$211,700
Clear Creek County8,994−4.0%144$94,577$608,500
San Miguel County7,753−3.9%64$79,024$720,700
Lake County7,552+1.6%33$96,575$466,100
Conejos County7,529+0.9%72$50,978$193,400
Kit Carson County7,069−0.2%62$70,259$239,500
Huerfano County7,011+2.9%33$52,526$247,800
Saguache County6,732+5.6%52$50,082$212,600
Rio Blanco County6,683+2.4%22$65,473$274,400
Gilpin County6,073+4.7%42$95,361$573,900
Bent County5,716+1.3%32$50,179$146,900
Crowley County5,677−4.2%42$48,826$116,200
Lincoln County5,645−0.6%42$62,861$246,500
Custer County5,590+18.8%22$72,674$392,100
Ouray County5,265+7.9%52$91,020$739,800
Washington County4,732−1.7%32$67,167$226,200
Phillips County4,420−2.5%42$64,674$258,200
Costilla County3,679+5.3%42$36,861$184,700
Baca County3,347−4.5%62$46,215$122,900
Dolores County2,466+6.1%21$64,907$247,600
Sedgwick County2,247−6.5%31$52,386$149,000
Cheyenne County1,713−2.1%31$70,865$187,500
Kiowa County1,412−2.4%51$58,618$161,500
Jackson County1,211−12.2%11$47,667$239,600
Mineral County910+5.2%11$56,250$430,500
San Juan County813+15.5%11$77,824$432,500
Hinsdale County753−4.0%31$75,972$437,900

Source: PEP Vintage 2025 (CO-EST2025); American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Census population estimates

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections