| Collingsworth | 3,200 | Wellington | Texas | Amarillo, TX | View → |
| Columbia | 61,000 | Hudson | New York | Albany-Utica-Elmira, NY | View → |
| Columbiana | 101,000 | Salem | Ohio | Cleveland-Youngstown, OH | View → |
| Comanche | 13,500 | Comanche | Texas | Dallas-Fort Worth, TX | View → |
| Concho | 4,000 | Eden | Texas | Austin-Waco, TX | View → |
| Conejos | 8,000 | Conejos | Colorado | Denver-Colorado Springs, CO | View → |
| Converse | 14,000 | Douglas | Wyoming | Casper, WY | View → |
| Cook | 5,100,000 | Chicago | Illinois | Chicago, IL | View → |
| Cook | 5,500 | Grand Marais | Minnesota | Green Bay, WI-Duluth, MN | View → |
| Cooke | 43,000 | Gainesville | Texas | Dallas-Fort Worth, TX | View → |
| Corson | 4,200 | McIntosh | South Dakota | Bismarck, ND | View → |
| Cortland | 47,000 | Cortland | New York | Buffalo-Rochester-Syracuse, NY | View → |
| Coryell | 78,000 | Gatesville | Texas | Austin-Waco, TX | View → |
| Coshocton | 36,500 | Coshocton | Ohio | Columbus, OH | View → |
| Costilla | 4,000 | San Luis | Colorado | Albuquerque, NM | View → |
| Cottle | 1,400 | Paducah | Texas | Amarillo, TX | View → |
| Coweta | 155,000 | Newnan | Georgia | Atlanta, GA | View → |
| Crane | 4,600 | Crane | Texas | El Paso-Odessa, TX | View → |
| Crawford | 19,000 | Robinson | Illinois | Champaign-Peoria, IL | View → |
| Crawford | 41,600 | Bucyrus | Ohio | Columbus, OH | View → |
| Crockett | 3,400 | Ozona | Texas | El Paso-Odessa, TX | View → |
| Crook | 7,500 | Sundance | Wyoming | Casper, WY | View → |
| Crowley | 6,000 | Ordway | Colorado | Denver-Colorado Springs, CO | View → |
| Culberson | 2,300 | Van Horn | Texas | El Paso-Odessa, TX | View → |
| Cullman | 87,900 | Cullman | Alabama | Birmingham-Huntsville, AL | View → |
| Cumberland | 11,000 | Toledo | Illinois | Champaign-Peoria, IL | View → |
| Curry | 48,500 | Clovis | New Mexico | Amarillo, TX | View → |
| Custer | 4,300 | Challis | Idaho | Boise-Pocatello, ID | View → |
| Custer | 5,000 | Westcliffe | Colorado | Denver-Colorado Springs, CO | View → |
| Cuyahoga | 1,210,000 | Cleveland | Ohio | Cleveland-Youngstown, OH | View → |
| Dallam | 6,700 | Dalhart | Texas | Amarillo, TX | View → |
| Dallas | 2,670,000 | Dallas | Texas | Dallas-Fort Worth, TX | View → |
| Dallas | 106,000 | Adel | Iowa | Des Moines, IA | View → |
| Daniels | 1,800 | Scobey | Montana | Bismarck, ND | View → |
| Darke | 50,500 | Greenville | Ohio | Cincinnati-Dayton, OH | View → |
| Darlington | 65,000 | Darlington | South Carolina | Charleston-Florence, SC | View → |
| Davidson | 168,000 | Lexington | North Carolina | Charlotte-Greensboro, NC | View → |
| Davie | 44,000 | Mocksville | North Carolina | Charlotte-Greensboro, NC | View → |
| Dawes | 8,800 | Chadron | Nebraska | Denver-Colorado Springs, CO | View → |
| Dawson | 27,000 | Dawsonville | Georgia | Atlanta, GA | View → |
| De Baca | 1,800 | Fort Sumner | New Mexico | Albuquerque, NM | View → |
| Deaf Smith | 19,000 | Hereford | Texas | Amarillo, TX | View → |
| Dearborn | 49,000 | Lawrenceburg | Indiana | Cincinnati-Dayton, OH | View → |
| Decatur | 7,900 | Leon | Iowa | Des Moines, IA | View → |
| Defiance | 38,100 | Defiance | Ohio | Detroit, MI-Toledo, OH | View → |
| DeKalb | 760,000 | Decatur | Georgia | Atlanta, GA | View → |
| DeKalb | 71,600 | Fort Payne | Alabama | Birmingham-Huntsville, AL | View → |
| DeKalb | 105,000 | DeKalb | Illinois | Chicago, IL | View → |
| Delaware | 18,000 | Manchester | Iowa | Cedar Rapids, IA | View → |
| Delaware | 215,000 | Delaware | Ohio | Columbus, OH | View → |
