US counties starting with C
370 counties and county-equivalents, which is 12% of the 3,144 in the United States. They are spread across 46 states. Sort any column, or select a county for its map and full data.
Every county beginning with C
| Name | State | Population | Land area | Density | Median income | Seat | FIPS |
|---|---|---|---|---|---|---|---|
| Cabarrus County | North Carolina | 249,725 | 361.2 sq mi | 691 per sq mi | $89,005 | Concord | 37025 |
| Cabell County | West Virginia | 91,183 | 281 sq mi | 324 per sq mi | $55,832 | Huntington | 54011 |
| Cache County | Utah | 145,000 | 1,165 sq mi | 124 per sq mi | $81,665 | Logan | 49005 |
| Caddo Parish | Louisiana | 224,226 | 879.5 sq mi | 255 per sq mi | $50,705 | Shreveport | 22017 |
| Caddo County | Oklahoma | 26,130 | 1,278 sq mi | 20.4 per sq mi | $55,353 | Anadarko | 40015 |
| Calaveras County | California | 46,605 | 1,020 sq mi | 45.7 per sq mi | $78,647 | San Andreas | 06009 |
| Calcasieu Parish | Louisiana | 208,466 | 1,064 sq mi | 196 per sq mi | $67,564 | Lake Charles | 22019 |
| Caldwell County | Kentucky | 12,609 | 344.8 sq mi | 36.6 per sq mi | $59,583 | Princeton | 21033 |
| Caldwell Parish | Louisiana | 9,344 | 529.8 sq mi | 17.6 per sq mi | $47,028 | Columbia | 22021 |
| Caldwell County | Missouri | 9,012 | 426.4 sq mi | 21.1 per sq mi | $64,806 | Kingston | 29025 |
| Caldwell County | North Carolina | 81,105 | 471.9 sq mi | 172 per sq mi | $56,425 | Lenoir | 37027 |
| Caldwell County | Texas | 55,150 | 544.5 sq mi | 101 per sq mi | $69,758 | Lockhart | 48055 |
| Caledonia County | Vermont | 30,414 | 649.2 sq mi | 46.8 per sq mi | $69,970 | St. Johnsbury | 50005 |
| Calhoun County | Alabama | 115,834 | 605.9 sq mi | 191 per sq mi | $55,029 | Anniston | 01015 |
| Calhoun County | Arkansas | 4,632 | 628.6 sq mi | 7.4 per sq mi | $66,809 | Hampton | 05013 |
| Calhoun County | Florida | 13,289 | 567.3 sq mi | 23.4 per sq mi | $50,517 | Blountstown | 12013 |
| Calhoun County | Georgia | 5,413 | 280.4 sq mi | 19.3 per sq mi | $46,940 | Morgan | 13037 |
| Calhoun County | Illinois | 4,300 | 253.8 sq mi | 16.9 per sq mi | $93,203 | Hardin | 17013 |
| Calhoun County | Iowa | 9,562 | 569.8 sq mi | 16.8 per sq mi | $64,964 | Rockwell City | 19025 |
| Calhoun County | Michigan | 133,408 | 706.3 sq mi | 189 per sq mi | $63,177 | Marshall | 26025 |
| Calhoun County | Mississippi | 12,643 | 586.6 sq mi | 21.6 per sq mi | $43,125 | Pittsboro | 28013 |
| Calhoun County | South Carolina | 14,188 | 381.1 sq mi | 37.2 per sq mi | $58,682 | St. Matthews | 45017 |
| Calhoun County | Texas | 19,599 | 506.9 sq mi | 38.7 per sq mi | $79,959 | Port Lavaca | 48057 |
| Calhoun County | West Virginia | 5,978 | 279.3 sq mi | 21.4 per sq mi | $43,980 | Grantsville | 54013 |
| Callahan County | Texas | 14,491 | 899.4 sq mi | 16.1 per sq mi | $72,436 | Baird | 48059 |
| Callaway County | Missouri | 45,765 | 834.6 sq mi | 54.8 per sq mi | $74,176 | Fulton | 29027 |
| Calloway County | Kentucky | 39,421 | 384.9 sq mi | 102 per sq mi | $52,706 | Murray | 21035 |
| Calumet County | Wisconsin | 53,982 | 318.3 sq mi | 170 per sq mi | $88,810 | Chilton | 55015 |
| Calvert County | Maryland | 94,484 | 213.2 sq mi | 443 per sq mi | $133,922 | Prince Frederick | 24009 |
| Camas County | Idaho | 1,316 | 1,074 sq mi | 1.2 per sq mi | $57,955 | Fairfield | 16025 |
| Cambria County | Pennsylvania | 128,968 | 688 sq mi | 187 per sq mi | $58,418 | Ebensburg | 42021 |
| Camden County | Georgia | 60,143 | 630.3 sq mi | 95.4 per sq mi | $74,378 | Woodbine | 13039 |
| Camden County | Missouri | 44,047 | 655.9 sq mi | 67.2 per sq mi | $66,387 | Camdenton | 29029 |
| Camden County | New Jersey | 535,799 | 221.4 sq mi | 2,420 per sq mi | $88,755 | Camden | 34007 |
| Camden County | North Carolina | 11,315 | 240.3 sq mi | 47.1 per sq mi | $91,078 | Camden | 37029 |
| Cameron Parish | Louisiana | 4,718 | 1,285 sq mi | 3.7 per sq mi | $75,278 | Cameron | 22023 |
| Cameron County | Pennsylvania | 4,211 | 396.2 sq mi | 10.6 per sq mi | $50,573 | Emporium | 42023 |
| Cameron County | Texas | 433,946 | 891.7 sq mi | 487 per sq mi | $52,601 | Brownsville | 48061 |
| Camp County | Texas | 13,380 | 195.8 sq mi | 68.3 per sq mi | $58,843 | Pittsburg | 48063 |
| Campbell County | Kentucky | 95,441 | 151.3 sq mi | 631 per sq mi | $77,567 | Alexandria | 21037 |
| Campbell County | South Dakota | 1,377 | 733.8 sq mi | 1.9 per sq mi | $68,929 | Mound City | 46021 |
| Campbell County | Tennessee | 40,290 | 480.2 sq mi | 83.9 per sq mi | $51,557 | Jacksboro | 47013 |
| Campbell County | Virginia | 55,629 | 503.3 sq mi | 111 per sq mi | $66,165 | Rustburg | 51031 |
| Campbell County | Wyoming | 48,145 | 4,802 sq mi | 10.0 per sq mi | $89,869 | Gillette | 56005 |
| Canadian County | Oklahoma | 187,189 | 896.6 sq mi | 209 per sq mi | $87,751 | El Reno | 40017 |
| Candler County | Georgia | 11,275 | 243.1 sq mi | 46.4 per sq mi | $49,581 | Metter | 13043 |
| Cannon County | Tennessee | 15,296 | 265.6 sq mi | 57.6 per sq mi | $59,443 | Woodbury | 47015 |
| Canyon County | Idaho | 275,123 | 587 sq mi | 469 per sq mi | $76,488 | Caldwell | 16027 |
| Cape Girardeau County | Missouri | 83,999 | 578.5 sq mi | 145 per sq mi | $68,464 | Jackson | 29031 |
| Cape May County | New Jersey | 93,390 | 251.5 sq mi | 371 per sq mi | $91,128 | Middle Township | 34009 |
| Capitol Planning Region | Connecticut | 994,115 | 1,027 sq mi | 968 per sq mi | $93,394 | Not available | 09110 |
| Carbon County | Montana | 11,466 | 2,048 sq mi | 5.6 per sq mi | $80,261 | Red Lodge | 30009 |
| Carbon County | Pennsylvania | 65,868 | 381.4 sq mi | 173 per sq mi | $67,554 | Jim Thorpe | 42025 |
| Carbon County | Utah | 20,680 | 1,479 sq mi | 14.0 per sq mi | $58,377 | Price | 49007 |
| Carbon County | Wyoming | 14,013 | 7,898 sq mi | 1.8 per sq mi | $70,511 | Rawlins | 56007 |
| Caribou County | Idaho | 7,252 | 1,764 sq mi | 4.1 per sq mi | $68,782 | Soda Springs | 16029 |
| Carlisle County | Kentucky | 4,747 | 189.5 sq mi | 25.1 per sq mi | $62,439 | Bardwell | 21039 |
| Carlton County | Minnesota | 36,711 | 861.2 sq mi | 42.6 per sq mi | $80,573 | Carlton | 27017 |
| Caroline County | Maryland | 34,116 | 319.4 sq mi | 107 per sq mi | $68,457 | Denton | 24011 |
| Caroline County | Virginia | 34,413 | 527.4 sq mi | 65.3 per sq mi | $87,407 | Bowling Green | 51033 |
| Carroll County | Arkansas | 29,263 | 629.9 sq mi | 46.5 per sq mi | $54,230 | Berryville | 05015 |
| Carroll County | Georgia | 131,036 | 499.1 sq mi | 263 per sq mi | $73,714 | Carrollton | 13045 |
| Carroll County | Illinois | 15,419 | 445.4 sq mi | 34.6 per sq mi | $60,758 | Mount Carroll | 17015 |
| Carroll County | Indiana | 20,655 | 372.2 sq mi | 55.5 per sq mi | $65,645 | Delphi | 18015 |
| Carroll County | Iowa | 20,303 | 569.5 sq mi | 35.7 per sq mi | $72,930 | Carroll | 19027 |
| Carroll County | Kentucky | 11,141 | 128.7 sq mi | 86.6 per sq mi | $56,466 | Carrollton | 21041 |
| Carroll County | Maryland | 176,677 | 447.6 sq mi | 395 per sq mi | $118,211 | Westminster | 24013 |
| Carroll County | Mississippi | 9,226 | 628.4 sq mi | 14.7 per sq mi | $59,327 | Carrollton | 28015 |
| Carroll County | Missouri | 8,417 | 694.6 sq mi | 12.1 per sq mi | $62,154 | Carrollton | 29033 |
| Carroll County | New Hampshire | 52,784 | 931.9 sq mi | 56.6 per sq mi | $86,463 | Ossipee | 33003 |
| Carroll County | Ohio | 26,475 | 394.7 sq mi | 67.1 per sq mi | $64,835 | Carrollton | 39019 |
| Carroll County | Tennessee | 29,200 | 597.7 sq mi | 48.9 per sq mi | $51,787 | Huntingdon | 47017 |
| Carroll County | Virginia | 29,299 | 474.7 sq mi | 61.7 per sq mi | $54,484 | Hillsville | 51035 |
| Carson County | Texas | 5,805 | 920.2 sq mi | 6.3 per sq mi | $85,231 | Panhandle | 48065 |
| Carson City | Nevada | 58,571 | 144.5 sq mi | 405 per sq mi | $72,355 | Carson City | 32510 |
| Carter County | Kentucky | 26,149 | 409.5 sq mi | 63.9 per sq mi | $51,235 | Grayson | 21043 |
| Carter County | Missouri | 5,418 | 507.4 sq mi | 10.7 per sq mi | $50,000 | Van Buren | 29035 |
| Carter County | Montana | 1,383 | 3,340 sq mi | 0.41 per sq mi | $54,167 | Ekalaka | 30011 |
| Carter County | Oklahoma | 48,910 | 822.3 sq mi | 59.5 per sq mi | $60,723 | Ardmore | 40019 |
| Carter County | Tennessee | 57,361 | 341.3 sq mi | 168 per sq mi | $50,135 | Elizabethton | 47019 |
| Carteret County | North Carolina | 70,469 | 507.6 sq mi | 139 per sq mi | $72,322 | Beaufort | 37031 |
| Carver County | Minnesota | 114,379 | 353.9 sq mi | 323 per sq mi | $125,946 | Chaska | 27019 |
| Cascade County | Montana | 85,029 | 2,698 sq mi | 31.5 per sq mi | $67,690 | Great Falls | 30013 |
| Casey County | Kentucky | 16,205 | 444.3 sq mi | 36.5 per sq mi | $45,510 | Liberty | 21045 |
| Cass County | Illinois | 12,463 | 375.8 sq mi | 33.2 per sq mi | $68,125 | Virginia | 17017 |
| Cass County | Indiana | 37,836 | 412.1 sq mi | 91.8 per sq mi | $56,403 | Logansport | 18017 |
| Cass County | Iowa | 12,960 | 564.3 sq mi | 23.0 per sq mi | $63,013 | Atlantic | 19029 |
| Cass County | Michigan | 51,677 | 490.1 sq mi | 105 per sq mi | $70,443 | Cassopolis | 26027 |
| Cass County | Minnesota | 31,430 | 2,021 sq mi | 15.5 per sq mi | $68,874 | Walker | 27021 |
| Cass County | Missouri | 115,859 | 696.6 sq mi | 166 per sq mi | $87,535 | Harrisonville | 29037 |
| Cass County | Nebraska | 27,657 | 556.9 sq mi | 49.7 per sq mi | $91,836 | Plattsmouth | 31025 |
| Cass County | North Dakota | 201,794 | 1,765 sq mi | 114 per sq mi | $75,555 | Fargo | 38017 |
| Cass County | Texas | 28,651 | 936.9 sq mi | 30.6 per sq mi | $53,813 | Linden | 48067 |
| Cassia County | Idaho | 26,397 | 2,566 sq mi | 10.3 per sq mi | $70,830 | Burley | 16031 |
| Castro County | Texas | 7,295 | 894.4 sq mi | 8.2 per sq mi | $56,776 | Dimmitt | 48069 |
| Caswell County | North Carolina | 22,563 | 425.5 sq mi | 53.0 per sq mi | $59,755 | Yanceyville | 37033 |
| Catahoula Parish | Louisiana | 8,223 | 709.3 sq mi | 11.6 per sq mi | $50,275 | Harrisonburg | 22025 |
| Catawba County | North Carolina | 170,172 | 401.4 sq mi | 424 per sq mi | $67,864 | Newton | 37035 |
| Catoosa County | Georgia | 69,628 | 162.2 sq mi | 429 per sq mi | $74,639 | Ringgold | 13047 |
| Catron County | New Mexico | 3,827 | 6,924 sq mi | 0.55 per sq mi | $49,864 | Reserve | 35003 |
| Cattaraugus County | New York | 75,390 | 1,308 sq mi | 57.6 per sq mi | $59,540 | Little Valley | 36009 |
| Cavalier County | North Dakota | 3,497 | 1,489 sq mi | 2.4 per sq mi | $69,531 | Langdon | 38019 |
| Cayuga County | New York | 74,365 | 691.6 sq mi | 108 per sq mi | $67,904 | Auburn | 36011 |
| Cecil County | Maryland | 107,131 | 346.3 sq mi | 309 per sq mi | $92,007 | Elkton | 24015 |
| Cedar County | Iowa | 18,359 | 579.5 sq mi | 31.7 per sq mi | $80,602 | Tipton | 19031 |
| Cedar County | Missouri | 14,888 | 474.5 sq mi | 31.4 per sq mi | $48,181 | Stockton | 29039 |
| Cedar County | Nebraska | 8,373 | 740.2 sq mi | 11.3 per sq mi | $73,578 | Hartington | 31027 |
| Centre County | Pennsylvania | 157,393 | 1,107 sq mi | 142 per sq mi | $74,291 | Bellefonte | 42027 |
| Cerro Gordo County | Iowa | 42,372 | 568.3 sq mi | 74.6 per sq mi | $68,189 | Mason City | 19033 |
| Chaffee County | Colorado | 20,831 | 1,013 sq mi | 20.6 per sq mi | $84,132 | Salida | 08015 |
| Chambers County | Alabama | 34,253 | 596.6 sq mi | 57.4 per sq mi | $49,656 | LaFayette | 01017 |
| Chambers County | Texas | 57,594 | 597.2 sq mi | 96.4 per sq mi | $109,804 | Anahuac | 48071 |
| Champaign County | Illinois | 209,972 | 996.1 sq mi | 211 per sq mi | $63,683 | Urbana | 17019 |
| Champaign County | Ohio | 38,820 | 429 sq mi | 90.5 per sq mi | $75,556 | Urbana | 39021 |
| Chariton County | Missouri | 7,377 | 751.2 sq mi | 9.8 per sq mi | $71,520 | Keytesville | 29041 |
| Charles County | Maryland | 176,593 | 457.8 sq mi | 386 per sq mi | $122,816 | La Plata | 24017 |
| Charles City County | Virginia | 6,623 | 182.9 sq mi | 36.2 per sq mi | $75,417 | Charles City | 51036 |
| Charles Mix County | South Dakota | 9,303 | 1,097 sq mi | 8.5 per sq mi | $64,038 | Lake Andes | 46023 |
| Charleston County | South Carolina | 436,200 | 918.1 sq mi | 475 per sq mi | $88,494 | Charleston | 45019 |
| Charlevoix County | Michigan | 26,036 | 416.3 sq mi | 62.5 per sq mi | $76,531 | Charlevoix | 26029 |
| Charlotte County | Florida | 217,212 | 681.1 sq mi | 319 per sq mi | $69,952 | Punta Gorda | 12015 |
| Charlotte County | Virginia | 11,401 | 475.3 sq mi | 24.0 per sq mi | $58,000 | Charlotte Court House | 51037 |
| Charlottesville city | Virginia | 44,388 | 10.2 sq mi | 4,333 per sq mi | $74,824 | Charlottesville city | 51540 |
| Charlton County | Georgia | 13,121 | 780.1 sq mi | 16.8 per sq mi | $61,276 | Folkston | 13049 |
| Chase County | Kansas | 2,572 | 773.1 sq mi | 3.3 per sq mi | $56,484 | Cottonwood Falls | 20017 |
| Chase County | Nebraska | 3,718 | 894.4 sq mi | 4.2 per sq mi | $68,173 | Imperial | 31029 |
| Chatham County | Georgia | 311,855 | 432.8 sq mi | 721 per sq mi | $71,097 | Savannah | 13051 |
| Chatham County | North Carolina | 85,111 | 681.5 sq mi | 125 per sq mi | $94,317 | Pittsboro | 37037 |
| Chattahoochee County | Georgia | 8,465 | 248.7 sq mi | 34.0 per sq mi | $61,042 | Cusseta | 13053 |
| Chattooga County | Georgia | 25,300 | 313.3 sq mi | 80.7 per sq mi | $50,285 | Summerville | 13055 |
| Chautauqua County | Kansas | 3,321 | 638.9 sq mi | 5.2 per sq mi | $56,438 | Sedan | 20019 |
| Chautauqua County | New York | 124,126 | 1,060 sq mi | 117 per sq mi | $58,351 | Mayville | 36013 |
| Chaves County | New Mexico | 63,364 | 6,067 sq mi | 10.4 per sq mi | $52,938 | Roswell | 35005 |
| Cheatham County | Tennessee | 42,778 | 302.5 sq mi | 141 per sq mi | $89,852 | Ashland City | 47021 |
| Cheboygan County | Michigan | 25,793 | 715.3 sq mi | 36.1 per sq mi | $62,875 | Cheboygan | 26031 |
| Chelan County | Washington | 81,941 | 2,921 sq mi | 28.1 per sq mi | $82,381 | Wenatchee | 53007 |
| Chemung County | New York | 80,415 | 407.3 sq mi | 197 per sq mi | $63,716 | Elmira | 36015 |
| Chenango County | New York | 45,715 | 893.4 sq mi | 51.2 per sq mi | $62,948 | Norwich | 36017 |
| Cherokee County | Alabama | 26,413 | 553.6 sq mi | 47.7 per sq mi | $53,863 | Centre | 01019 |
| Cherokee County | Georgia | 299,273 | 421 sq mi | 711 per sq mi | $108,115 | Canton | 13057 |
| Cherokee County | Iowa | 11,369 | 576.9 sq mi | 19.7 per sq mi | $71,269 | Cherokee | 19035 |
| Cherokee County | Kansas | 19,105 | 587.6 sq mi | 32.5 per sq mi | $57,668 | Columbus | 20021 |
| Cherokee County | North Carolina | 30,830 | 455.5 sq mi | 67.7 per sq mi | $53,628 | Murphy | 37039 |
| Cherokee County | Oklahoma | 49,196 | 749.1 sq mi | 65.7 per sq mi | $53,218 | Tahlequah | 40021 |
| Cherokee County | South Carolina | 58,275 | 393 sq mi | 148 per sq mi | $50,288 | Gaffney | 45021 |
| Cherokee County | Texas | 53,337 | 1,053 sq mi | 50.7 per sq mi | $61,261 | Rusk | 48073 |
| Cherry County | Nebraska | 5,561 | 5,960 sq mi | 0.93 per sq mi | $66,270 | Valentine | 31031 |
| Chesapeake city | Virginia | 255,332 | 338.5 sq mi | 754 per sq mi | $95,373 | Chesapeake city | 51550 |
| Cheshire County | New Hampshire | 78,269 | 706.7 sq mi | 111 per sq mi | $83,329 | Keene | 33005 |
| Chester County | Pennsylvania | 557,116 | 750.6 sq mi | 742 per sq mi | $127,208 | West Chester | 42029 |
| Chester County | South Carolina | 33,001 | 580.9 sq mi | 56.8 per sq mi | $52,458 | Chester | 45023 |
| Chester County | Tennessee | 17,994 | 285.7 sq mi | 63.0 per sq mi | $59,341 | Henderson | 47023 |
| Chesterfield County | South Carolina | 44,740 | 799 sq mi | 56.0 per sq mi | $49,235 | Chesterfield | 45025 |
| Chesterfield County | Virginia | 397,148 | 423.5 sq mi | 938 per sq mi | $101,931 | Chesterfield Court House | 51041 |
| Cheyenne County | Colorado | 1,713 | 1,778 sq mi | 0.96 per sq mi | $70,865 | Cheyenne Wells | 08017 |
| Cheyenne County | Kansas | 2,604 | 1,020 sq mi | 2.6 per sq mi | $55,429 | St. Francis | 20023 |
| Cheyenne County | Nebraska | 9,528 | 1,196 sq mi | 8.0 per sq mi | $60,348 | Sidney | 31033 |
| Chickasaw County | Iowa | 11,663 | 504.3 sq mi | 23.1 per sq mi | $75,675 | New Hampton | 19037 |
| Chickasaw County | Mississippi | 16,730 | 501.8 sq mi | 33.3 per sq mi | $43,586 | Houston | 28017 |
| Chicot County | Arkansas | 9,107 | 637 sq mi | 14.3 per sq mi | $39,045 | Lake Village | 05017 |
| Childress County | Texas | 6,643 | 696.5 sq mi | 9.5 per sq mi | $58,654 | Childress | 48075 |
| Chilton County | Alabama | 47,708 | 692.8 sq mi | 68.9 per sq mi | $65,603 | Clanton | 01021 |
| Chippewa County | Michigan | 36,081 | 1,559 sq mi | 23.2 per sq mi | $62,217 | Sault Ste. Marie | 26033 |
| Chippewa County | Minnesota | 12,406 | 581.2 sq mi | 21.3 per sq mi | $71,458 | Montevideo | 27023 |
| Chippewa County | Wisconsin | 67,614 | 1,008 sq mi | 67.0 per sq mi | $74,680 | Chippewa Falls | 55017 |
| Chisago County | Minnesota | 59,142 | 414.9 sq mi | 143 per sq mi | $99,400 | Center City | 27025 |
| Chittenden County | Vermont | 169,115 | 536.9 sq mi | 315 per sq mi | $96,759 | Burlington | 50007 |
| Choctaw County | Alabama | 11,904 | 913.5 sq mi | 13.0 per sq mi | $47,813 | Butler | 01023 |
| Choctaw County | Mississippi | 8,048 | 418.2 sq mi | 19.2 per sq mi | $50,919 | Ackerman | 28019 |
| Choctaw County | Oklahoma | 14,059 | 770.4 sq mi | 18.2 per sq mi | $44,081 | Hugo | 40023 |
| Chouteau County | Montana | 5,865 | 3,973 sq mi | 1.5 per sq mi | $58,218 | Fort Benton | 30015 |
| Chowan County | North Carolina | 14,082 | 172.7 sq mi | 81.6 per sq mi | $53,864 | Edenton | 37041 |
| Christian County | Illinois | 33,443 | 709.5 sq mi | 47.1 per sq mi | $62,611 | Taylorville | 17021 |
| Christian County | Kentucky | 70,115 | 717.8 sq mi | 97.7 per sq mi | $55,494 | Hopkinsville | 21047 |
| Christian County | Missouri | 96,725 | 562.6 sq mi | 172 per sq mi | $83,437 | Ozark | 29043 |
| Chugach Census Area | Alaska | 6,553 | 9,574 sq mi | 0.68 per sq mi | $90,509 | Not available | 02063 |
| Churchill County | Nevada | 25,851 | 4,950 sq mi | 5.2 per sq mi | $79,163 | Fallon | 32001 |
| Cibola County | New Mexico | 26,807 | 4,540 sq mi | 5.9 per sq mi | $50,759 | Grants | 35006 |
| Cimarron County | Oklahoma | 2,059 | 1,835 sq mi | 1.1 per sq mi | $62,188 | Boise City | 40025 |
| Citrus County | Florida | 171,666 | 582 sq mi | 295 per sq mi | $56,546 | Inverness | 12017 |
| Clackamas County | Oregon | 426,280 | 1,871 sq mi | 228 per sq mi | $103,517 | Oregon City | 41005 |
| Claiborne Parish | Louisiana | 13,354 | 754.8 sq mi | 17.7 per sq mi | $32,831 | Homer | 22027 |
| Claiborne County | Mississippi | 8,058 | 487.4 sq mi | 16.5 per sq mi | $31,897 | Port Gibson | 28021 |
| Claiborne County | Tennessee | 33,229 | 434.6 sq mi | 76.5 per sq mi | $49,379 | Tazewell | 47025 |
| Clallam County | Washington | 78,202 | 1,739 sq mi | 45.0 per sq mi | $70,370 | Port Angeles | 53009 |
| Clare County | Michigan | 31,543 | 564.4 sq mi | 55.9 per sq mi | $49,384 | Harrison | 26035 |
| Clarendon County | South Carolina | 31,043 | 607.2 sq mi | 51.1 per sq mi | $52,401 | Manning | 45027 |
| Clarion County | Pennsylvania | 36,680 | 600.8 sq mi | 61.0 per sq mi | $62,649 | Clarion | 42031 |
| Clark County | Arkansas | 20,938 | 866 sq mi | 24.2 per sq mi | $52,034 | Arkadelphia | 05019 |
| Clark County | Idaho | 783 | 1,763 sq mi | 0.44 per sq mi | $55,208 | Dubois | 16033 |
| Clark County | Illinois | 15,114 | 501.4 sq mi | 30.1 per sq mi | $72,927 | Marshall | 17023 |
| Clark County | Indiana | 130,451 | 372.5 sq mi | 350 per sq mi | $74,214 | Jeffersonville | 18019 |
| Clark County | Kansas | 1,900 | 974.6 sq mi | 2.0 per sq mi | $63,043 | Ashland | 20025 |
| Clark County | Kentucky | 37,888 | 252.5 sq mi | 150 per sq mi | $64,348 | Winchester | 21049 |
| Clark County | Missouri | 6,475 | 504.6 sq mi | 12.8 per sq mi | $51,781 | Kahoka | 29045 |
| Clark County | Nevada | 2,407,226 | 7,892 sq mi | 305 per sq mi | $76,472 | Las Vegas | 32003 |
| Clark County | Ohio | 135,340 | 395.9 sq mi | 342 per sq mi | $63,132 | Springfield | 39023 |
| Clark County | South Dakota | 4,031 | 957.5 sq mi | 4.2 per sq mi | $70,726 | Clark | 46025 |
| Clark County | Washington | 532,119 | 628.5 sq mi | 847 per sq mi | $97,536 | Vancouver | 53011 |
| Clark County | Wisconsin | 35,052 | 1,210 sq mi | 29.0 per sq mi | $67,400 | Neillsville | 55019 |
| Clarke County | Alabama | 22,014 | 1,238 sq mi | 17.8 per sq mi | $49,249 | Grove Hill | 01025 |
| Clarke County | Georgia | 129,921 | 119.3 sq mi | 1,089 per sq mi | $53,625 | Athens | 13059 |
| Clarke County | Iowa | 9,574 | 431.1 sq mi | 22.2 per sq mi | $71,641 | Osceola | 19039 |
| Clarke County | Mississippi | 15,102 | 691.6 sq mi | 21.8 per sq mi | $46,108 | Quitman | 28023 |
| Clarke County | Virginia | 15,609 | 176 sq mi | 88.7 per sq mi | $117,111 | Berryville | 51043 |
| Clatsop County | Oregon | 40,926 | 828.2 sq mi | 49.4 per sq mi | $71,822 | Astoria | 41007 |
| Clay County | Alabama | 14,207 | 604 sq mi | 23.5 per sq mi | $55,250 | Ashland | 01027 |
| Clay County | Arkansas | 14,052 | 639.2 sq mi | 22.0 per sq mi | $51,481 | Corning | 05021 |
| Clay County | Florida | 239,593 | 604.6 sq mi | 396 per sq mi | $87,820 | Green Cove Springs | 12019 |
| Clay County | Georgia | 2,815 | 195.4 sq mi | 14.4 per sq mi | $49,147 | Fort Gaines | 13061 |
| Clay County | Illinois | 12,793 | 468.4 sq mi | 27.3 per sq mi | $60,417 | Louisville | 17025 |
| Clay County | Indiana | 26,410 | 357.6 sq mi | 73.9 per sq mi | $70,010 | Brazil | 18021 |
| Clay County | Iowa | 16,202 | 567.2 sq mi | 28.6 per sq mi | $65,428 | Spencer | 19041 |
| Clay County | Kansas | 7,990 | 645.3 sq mi | 12.4 per sq mi | $66,176 | Clay Center | 20027 |
| Clay County | Kentucky | 19,465 | 469.3 sq mi | 41.5 per sq mi | $40,900 | Manchester | 21051 |
| Clay County | Minnesota | 67,734 | 1,045 sq mi | 64.8 per sq mi | $81,172 | Moorhead | 27027 |
| Clay County | Mississippi | 18,238 | 410 sq mi | 44.5 per sq mi | $43,125 | West Point | 28025 |
| Clay County | Missouri | 265,032 | 397.7 sq mi | 666 per sq mi | $88,468 | Liberty | 29047 |
| Clay County | Nebraska | 6,170 | 572.3 sq mi | 10.8 per sq mi | $78,986 | Clay Center | 31035 |
| Clay County | North Carolina | 12,239 | 215 sq mi | 56.9 per sq mi | $56,971 | Hayesville | 37043 |
| Clay County | South Dakota | 15,031 | 412 sq mi | 36.5 per sq mi | $56,850 | Vermillion | 46027 |
| Clay County | Tennessee | 7,821 | 236.5 sq mi | 33.1 per sq mi | $39,972 | Celina | 47027 |
| Clay County | Texas | 10,764 | 1,089 sq mi | 9.9 per sq mi | $80,114 | Henrietta | 48077 |
| Clay County | West Virginia | 7,538 | 342 sq mi | 22.0 per sq mi | $42,318 | Clay | 54015 |
| Clayton County | Georgia | 297,471 | 141.7 sq mi | 2,099 per sq mi | $59,806 | Jonesboro | 13063 |
| Clayton County | Iowa | 16,845 | 778.5 sq mi | 21.6 per sq mi | $67,242 | Elkader | 19043 |
| Clear Creek County | Colorado | 8,994 | 395.1 sq mi | 22.8 per sq mi | $94,577 | Georgetown | 08019 |
| Clearfield County | Pennsylvania | 78,100 | 1,145 sq mi | 68.2 per sq mi | $62,152 | Clearfield | 42033 |
| Clearwater County | Idaho | 9,118 | 2,457 sq mi | 3.7 per sq mi | $60,000 | Orofino | 16035 |
| Clearwater County | Minnesota | 8,647 | 999 sq mi | 8.7 per sq mi | $64,475 | Bagley | 27029 |
| Cleburne County | Alabama | 15,970 | 560.1 sq mi | 28.5 per sq mi | $55,345 | Heflin | 01029 |
| Cleburne County | Arkansas | 25,672 | 554 sq mi | 46.3 per sq mi | $55,798 | Heber Springs | 05023 |
| Clermont County | Ohio | 216,977 | 452.6 sq mi | 479 per sq mi | $85,510 | Batavia | 39025 |
| Cleveland County | Arkansas | 7,224 | 597.9 sq mi | 12.1 per sq mi | $54,794 | Rison | 05025 |
| Cleveland County | North Carolina | 103,325 | 464.3 sq mi | 223 per sq mi | $58,534 | Shelby | 37045 |
| Cleveland County | Oklahoma | 303,973 | 538.9 sq mi | 564 per sq mi | $77,068 | Norman | 40027 |
| Clinch County | Georgia | 6,847 | 815 sq mi | 8.4 per sq mi | $45,847 | Homerville | 13065 |
| Clinton County | Illinois | 37,128 | 473.9 sq mi | 78.3 per sq mi | $86,588 | Carlyle | 17027 |
| Clinton County | Indiana | 33,322 | 405.1 sq mi | 82.3 per sq mi | $65,019 | Frankfort | 18023 |
| Clinton County | Iowa | 46,002 | 695 sq mi | 66.2 per sq mi | $66,981 | Clinton | 19045 |
| Clinton County | Kentucky | 9,139 | 197.1 sq mi | 46.4 per sq mi | $44,844 | Albany | 21053 |
| Clinton County | Michigan | 80,432 | 567.3 sq mi | 142 per sq mi | $88,210 | St. Johns | 26037 |
| Clinton County | Missouri | 21,661 | 418.9 sq mi | 51.7 per sq mi | $70,627 | Plattsburg | 29049 |
| Clinton County | New York | 78,138 | 1,038 sq mi | 75.3 per sq mi | $71,224 | Plattsburgh | 36019 |
| Clinton County | Ohio | 42,301 | 408.7 sq mi | 103 per sq mi | $70,407 | Wilmington | 39027 |
| Clinton County | Pennsylvania | 37,870 | 889.6 sq mi | 42.6 per sq mi | $60,816 | Lock Haven | 42035 |
| Cloud County | Kansas | 8,833 | 715.3 sq mi | 12.3 per sq mi | $58,770 | Concordia | 20029 |
| Coahoma County | Mississippi | 19,849 | 553.1 sq mi | 35.9 per sq mi | $37,461 | Clarksdale | 28027 |
| Coal County | Oklahoma | 5,436 | 516.8 sq mi | 10.5 per sq mi | $50,423 | Coalgate | 40029 |
| Cobb County | Georgia | 793,345 | 339.7 sq mi | 2,335 per sq mi | $102,738 | Marietta | 13067 |
| Cochise County | Arizona | 126,332 | 6,210 sq mi | 20.3 per sq mi | $59,742 | Bisbee | 04003 |
| Cochran County | Texas | 2,546 | 775.1 sq mi | 3.3 per sq mi | $45,313 | Morton | 48079 |
| Cocke County | Tennessee | 37,889 | 436.1 sq mi | 86.9 per sq mi | $48,016 | Newport | 47029 |
| Coconino County | Arizona | 144,368 | 18,616 sq mi | 7.8 per sq mi | $72,966 | Flagstaff | 04005 |
| Codington County | South Dakota | 29,562 | 687.6 sq mi | 43.0 per sq mi | $72,727 | Watertown | 46029 |
| Coffee County | Alabama | 56,953 | 679.1 sq mi | 83.9 per sq mi | $68,353 | Elba | 01031 |
| Coffee County | Georgia | 44,407 | 592.3 sq mi | 75.0 per sq mi | $50,683 | Douglas | 13069 |
| Coffee County | Tennessee | 62,419 | 429 sq mi | 146 per sq mi | $61,505 | Manchester | 47031 |
| Coffey County | Kansas | 8,467 | 626.9 sq mi | 13.5 per sq mi | $70,346 | Burlington | 20031 |
| Coke County | Texas | 3,412 | 911.6 sq mi | 3.7 per sq mi | $43,333 | Robert Lee | 48081 |
| Colbert County | Alabama | 59,474 | 593 sq mi | 100 per sq mi | $60,628 | Tuscumbia | 01033 |
| Cole County | Missouri | 77,908 | 391.5 sq mi | 199 per sq mi | $74,876 | Jefferson City | 29051 |
| Coleman County | Texas | 7,915 | 1,263 sq mi | 6.3 per sq mi | $49,159 | Coleman | 48083 |
| Coles County | Illinois | 46,607 | 508.3 sq mi | 91.7 per sq mi | $56,478 | Charleston | 17029 |
| Colfax County | Nebraska | 10,934 | 411.5 sq mi | 26.6 per sq mi | $82,530 | Schuyler | 31037 |
| Colfax County | New Mexico | 12,184 | 3,758 sq mi | 3.2 per sq mi | $53,554 | Raton | 35007 |
| Colleton County | South Carolina | 39,382 | 1,057 sq mi | 37.3 per sq mi | $51,114 | Walterboro | 45029 |
| Collier County | Florida | 417,131 | 1,997 sq mi | 209 per sq mi | $90,045 | East Naples | 12021 |
| Collin County | Texas | 1,297,179 | 841.5 sq mi | 1,541 per sq mi | $121,600 | McKinney | 48085 |
| Collingsworth County | Texas | 2,487 | 918.4 sq mi | 2.7 per sq mi | $61,280 | Wellington | 48087 |
| Colonial Heights city | Virginia | 18,738 | 7.5 sq mi | 2,492 per sq mi | $76,505 | Colonial Heights city | 51570 |
| Colorado County | Texas | 21,439 | 960.3 sq mi | 22.3 per sq mi | $66,377 | Columbus | 48089 |
| Colquitt County | Georgia | 47,438 | 547.1 sq mi | 86.7 per sq mi | $49,341 | Moultrie | 13071 |
| Columbia County | Arkansas | 21,894 | 766.1 sq mi | 28.6 per sq mi | $55,334 | Magnolia | 05027 |
| Columbia County | Florida | 74,094 | 797.4 sq mi | 92.9 per sq mi | $59,205 | Lake City | 12023 |
| Columbia County | Georgia | 169,189 | 290.2 sq mi | 583 per sq mi | $95,592 | Appling | 13073 |
| Columbia County | New York | 60,168 | 634.7 sq mi | 94.8 per sq mi | $81,528 | Hudson | 36021 |
| Columbia County | Oregon | 54,091 | 658.7 sq mi | 82.1 per sq mi | $87,458 | St. Helens | 41009 |
| Columbia County | Pennsylvania | 66,193 | 483.3 sq mi | 137 per sq mi | $64,644 | Bloomsburg | 42037 |
| Columbia County | Washington | 4,141 | 868.6 sq mi | 4.8 per sq mi | $71,810 | Dayton | 53013 |
| Columbia County | Wisconsin | 58,132 | 765.6 sq mi | 75.9 per sq mi | $85,351 | Portage | 55021 |
| Columbiana County | Ohio | 99,377 | 531.9 sq mi | 187 per sq mi | $58,180 | Lisbon | 39029 |
| Columbus County | North Carolina | 50,487 | 938.2 sq mi | 53.8 per sq mi | $49,442 | Whiteville | 37047 |
| Colusa County | California | 21,836 | 1,151 sq mi | 19.0 per sq mi | $75,672 | Colusa | 06011 |
| Comal County | Texas | 209,166 | 559.5 sq mi | 374 per sq mi | $101,889 | New Braunfels | 48091 |
| Comanche County | Kansas | 1,673 | 788.3 sq mi | 2.1 per sq mi | $54,545 | Coldwater | 20033 |
| Comanche County | Oklahoma | 122,158 | 1,069 sq mi | 114 per sq mi | $60,761 | Lawton | 40031 |
| Comanche County | Texas | 14,432 | 937.8 sq mi | 15.4 per sq mi | $59,635 | Comanche | 48093 |
| Concho County | Texas | 3,607 | 983.8 sq mi | 3.7 per sq mi | $65,795 | Paint Rock | 48095 |
| Concordia Parish | Louisiana | 17,836 | 695.7 sq mi | 25.6 per sq mi | $39,943 | Vidalia | 22029 |
| Conecuh County | Alabama | 10,899 | 850.3 sq mi | 12.8 per sq mi | $41,327 | Evergreen | 01035 |
| Conejos County | Colorado | 7,529 | 1,287 sq mi | 5.9 per sq mi | $50,978 | Conejos | 08021 |
| Contra Costa County | California | 1,170,070 | 716.9 sq mi | 1,632 per sq mi | $127,229 | Martinez | 06013 |
| Converse County | Wyoming | 13,824 | 4,255 sq mi | 3.3 per sq mi | $81,558 | Douglas | 56009 |
| Conway County | Arkansas | 21,393 | 552 sq mi | 38.8 per sq mi | $54,187 | Morrilton | 05029 |
| Cook County | Georgia | 18,232 | 228.5 sq mi | 79.8 per sq mi | $53,651 | Adel | 13075 |
| Cook County | Illinois | 5,194,625 | 944.9 sq mi | 5,497 per sq mi | $83,498 | Chicago | 17031 |
| Cook County | Minnesota | 5,522 | 1,453 sq mi | 3.8 per sq mi | $72,638 | Grand Marais | 27031 |
| Cooke County | Texas | 44,461 | 874.8 sq mi | 50.8 per sq mi | $73,932 | Gainesville | 48097 |
| Cooper County | Missouri | 17,136 | 564.7 sq mi | 30.3 per sq mi | $70,625 | Boonville | 29053 |
| Coos County | New Hampshire | 31,343 | 1,795 sq mi | 17.5 per sq mi | $57,677 | Lancaster | 33007 |
| Coos County | Oregon | 63,992 | 1,596 sq mi | 40.1 per sq mi | $62,143 | Coquille | 41011 |
| Coosa County | Alabama | 10,161 | 650.9 sq mi | 15.6 per sq mi | $57,355 | Rockford | 01037 |
| Copiah County | Mississippi | 27,497 | 777.3 sq mi | 35.4 per sq mi | $49,089 | Hazlehurst | 28029 |
| Copper River Census Area | Alaska | 2,666 | 24,647 sq mi | 0.11 per sq mi | $79,250 | Not available | 02066 |
| Corson County | South Dakota | 3,781 | 2,470 sq mi | 1.5 per sq mi | $46,406 | McIntosh | 46031 |
| Cortland County | New York | 45,850 | 498.8 sq mi | 91.9 per sq mi | $70,418 | Cortland | 36023 |
| Coryell County | Texas | 85,592 | 1,052 sq mi | 81.3 per sq mi | $71,301 | Gatesville | 48099 |
| Coshocton County | Ohio | 37,188 | 563.9 sq mi | 65.9 per sq mi | $55,577 | Coshocton | 39031 |
| Costilla County | Colorado | 3,679 | 1,228 sq mi | 3.0 per sq mi | $36,861 | San Luis | 08023 |
| Cottle County | Texas | 1,224 | 900.6 sq mi | 1.4 per sq mi | $59,063 | Paducah | 48101 |
| Cotton County | Oklahoma | 5,432 | 632.6 sq mi | 8.6 per sq mi | $58,425 | Walters | 40033 |
| Cottonwood County | Minnesota | 11,405 | 640 sq mi | 17.8 per sq mi | $72,941 | Windom | 27033 |
| Covington County | Alabama | 37,947 | 1,031 sq mi | 36.8 per sq mi | $52,456 | Andalusia | 01039 |
| Covington County | Mississippi | 17,898 | 413.8 sq mi | 43.3 per sq mi | $45,051 | Collins | 28031 |
| Covington city | Virginia | 5,680 | 5.5 sq mi | 1,039 per sq mi | $41,944 | Covington city | 51580 |
| Coweta County | Georgia | 160,240 | 441 sq mi | 363 per sq mi | $95,548 | Newnan | 13077 |
| Cowley County | Kansas | 34,382 | 1,126 sq mi | 30.5 per sq mi | $57,878 | Winfield | 20035 |
| Cowlitz County | Washington | 114,885 | 1,141 sq mi | 101 per sq mi | $76,531 | Kelso | 53015 |
| Craig County | Oklahoma | 14,518 | 761.3 sq mi | 19.1 per sq mi | $51,922 | Vinita | 40035 |
| Craig County | Virginia | 4,800 | 328.1 sq mi | 14.6 per sq mi | $69,057 | New Castle | 51045 |
| Craighead County | Arkansas | 116,957 | 707.2 sq mi | 165 per sq mi | $59,548 | Jonesboro | 05031 |
| Crane County | Texas | 4,554 | 785.1 sq mi | 5.8 per sq mi | $62,212 | Crane | 48103 |
| Craven County | North Carolina | 105,025 | 706.5 sq mi | 149 per sq mi | $65,873 | New Bern | 37049 |
| Crawford County | Arkansas | 62,657 | 595.3 sq mi | 105 per sq mi | $64,132 | Van Buren | 05033 |
| Crawford County | Georgia | 12,206 | 324.9 sq mi | 37.6 per sq mi | $67,116 | Knoxville | 13079 |
| Crawford County | Illinois | 18,648 | 443.6 sq mi | 42.0 per sq mi | $71,674 | Robinson | 17033 |
| Crawford County | Indiana | 10,509 | 305.6 sq mi | 34.4 per sq mi | $49,640 | English | 18025 |
| Crawford County | Iowa | 16,237 | 714.2 sq mi | 22.7 per sq mi | $67,027 | Denison | 19047 |
| Crawford County | Kansas | 39,008 | 589.8 sq mi | 66.1 per sq mi | $52,844 | Girard | 20037 |
| Crawford County | Michigan | 13,722 | 556.4 sq mi | 24.7 per sq mi | $60,392 | Grayling | 26039 |
| Crawford County | Missouri | 22,929 | 742.5 sq mi | 30.9 per sq mi | $57,629 | Steelville | 29055 |
| Crawford County | Ohio | 41,896 | 401.8 sq mi | 104 per sq mi | $58,044 | Bucyrus | 39033 |
| Crawford County | Pennsylvania | 81,792 | 1,012 sq mi | 80.8 per sq mi | $60,476 | Meadville | 42039 |
| Crawford County | Wisconsin | 15,910 | 570.8 sq mi | 27.9 per sq mi | $64,094 | Prairie du Chien | 55023 |
| Creek County | Oklahoma | 74,967 | 949.9 sq mi | 78.9 per sq mi | $62,338 | Sapulpa | 40037 |
| Crenshaw County | Alabama | 13,175 | 608.9 sq mi | 21.6 per sq mi | $48,560 | Luverne | 01041 |
| Crisp County | Georgia | 19,237 | 272.7 sq mi | 70.5 per sq mi | $45,105 | Cordele | 13081 |
| Crittenden County | Arkansas | 46,210 | 611.8 sq mi | 75.5 per sq mi | $55,358 | Marion | 05035 |
| Crittenden County | Kentucky | 8,807 | 359.6 sq mi | 24.5 per sq mi | $46,656 | Marion | 21055 |
| Crockett County | Tennessee | 14,006 | 265.5 sq mi | 52.7 per sq mi | $62,165 | Alamo | 47033 |
| Crockett County | Texas | 2,769 | 2,807 sq mi | 0.99 per sq mi | $81,022 | Ozona | 48105 |
| Crook County | Oregon | 27,564 | 2,979 sq mi | 9.3 per sq mi | $81,965 | Prineville | 41013 |
| Crook County | Wyoming | 7,852 | 2,854 sq mi | 2.8 per sq mi | $79,637 | Sundance | 56011 |
| Crosby County | Texas | 4,852 | 900.2 sq mi | 5.4 per sq mi | $52,188 | Crosbyton | 48107 |
| Cross County | Arkansas | 16,186 | 616.3 sq mi | 26.3 per sq mi | $50,863 | Wynne | 05037 |
| Crow Wing County | Minnesota | 69,132 | 998.5 sq mi | 69.2 per sq mi | $72,589 | Brainerd | 27035 |
| Crowley County | Colorado | 5,677 | 787.4 sq mi | 7.2 per sq mi | $48,826 | Ordway | 08025 |
| Culberson County | Texas | 2,267 | 3,812 sq mi | 0.60 per sq mi | $58,777 | Van Horn | 48109 |
| Cullman County | Alabama | 94,009 | 734.7 sq mi | 128 per sq mi | $62,656 | Cullman | 01043 |
| Culpeper County | Virginia | 57,666 | 379.2 sq mi | 152 per sq mi | $100,049 | Culpeper | 51047 |
| Cumberland County | Illinois | 10,208 | 345.9 sq mi | 29.5 per sq mi | $73,327 | Toledo | 17035 |
| Cumberland County | Kentucky | 5,992 | 305.1 sq mi | 19.6 per sq mi | $40,000 | Burkesville | 21057 |
| Cumberland County | Maine | 317,222 | 836.2 sq mi | 379 per sq mi | $95,677 | Portland | 23005 |
| Cumberland County | New Jersey | 157,148 | 483.4 sq mi | 325 per sq mi | $67,436 | Bridgeton | 34011 |
| Cumberland County | North Carolina | 338,473 | 652.6 sq mi | 519 per sq mi | $61,291 | Fayetteville | 37051 |
| Cumberland County | Pennsylvania | 277,270 | 545.5 sq mi | 508 per sq mi | $87,494 | Carlisle | 42041 |
| Cumberland County | Tennessee | 66,300 | 681.3 sq mi | 97.3 per sq mi | $60,375 | Crossville | 47035 |
| Cumberland County | Virginia | 10,352 | 297.5 sq mi | 34.8 per sq mi | $55,325 | Cumberland | 51049 |
| Cuming County | Nebraska | 8,823 | 570.5 sq mi | 15.5 per sq mi | $71,104 | West Point | 31039 |
| Currituck County | North Carolina | 33,158 | 261.9 sq mi | 127 per sq mi | $93,511 | Currituck | 37053 |
| Curry County | New Mexico | 46,655 | 1,406 sq mi | 33.2 per sq mi | $57,309 | Clovis | 35009 |
| Curry County | Oregon | 22,621 | 1,628 sq mi | 13.9 per sq mi | $62,244 | Gold Beach | 41015 |
| Custer County | Colorado | 5,590 | 738.6 sq mi | 7.6 per sq mi | $72,674 | Westcliffe | 08027 |
| Custer County | Idaho | 4,636 | 4,922 sq mi | 0.94 per sq mi | $67,574 | Challis | 16037 |
| Custer County | Montana | 12,034 | 3,783 sq mi | 3.2 per sq mi | $70,605 | Miles City | 30017 |
| Custer County | Nebraska | 10,500 | 2,575 sq mi | 4.1 per sq mi | $67,906 | Broken Bow | 31041 |
| Custer County | Oklahoma | 28,175 | 988.8 sq mi | 28.5 per sq mi | $59,738 | Arapaho | 40039 |
| Custer County | South Dakota | 9,431 | 1,557 sq mi | 6.1 per sq mi | $84,112 | Custer | 46033 |
| Cuyahoga County | Ohio | 1,232,925 | 457.2 sq mi | 2,696 per sq mi | $64,468 | Cleveland | 39035 |
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Retrieved 30 August 2026.