| 1. | Douglas County, CO (Highlands Ranch, Parker, Castle Rock) (pop. 175,766) | 3.1 |
| 2. | Loudoun County, VA (Ashburn, Leesburg, Sterling) (pop. 169,599) | 3.2 |
| 3. | Prince William County, VA (Dale City, Manassas, Marumsco) (pop. 280,813) | 3.8 |
| 4. | Fort Bend County, TX (Sugar Land, Missouri City, Mission Bend) (pop. 354,452) | 3.9 |
| 5. | Utah County, UT (Provo, Orem, Pleasant Grove) (pop. 368,536) | 3.9 |
| 6. | Collin County, TX (Plano, McKinney, Allen) (pop. 491,675) | 4.0 |
| 7. | Kendall County, IL (Oswego, Boulder Hill, Yorkville) (pop. 54,544) | 4.1 |
| 8. | Gwinnett County, GA (Dacula-Rocky Creek, Lawrenceville, Duluth) (pop. 588,448) | 4.1 |
| 9. | Denton County, TX (Denton, Lewisville, Flower Mound) (pop. 432,976) | 4.1 |
| 10. | Scott County, MN (Savage, Shakopee, Prior Lake) (pop. 89,498) | 4.1 |
| 11. | Cache County, UT (Logan, Smithfield, Hyrum) (pop. 91,391) | 4.2 |
| 12. | Fairbanks North Star Borough, AK (Fairbanks, Badger, College) (pop. 82,840) | 4.2 |
| 13. | Fairfax County, VA (Burke, Reston, Annandale) (pop. 969,749) | 4.3 |
| 14. | Forsyth County, GA (Big Creek, Chestatee, Silver City) (pop. 98,407) | 4.4 |
| 15. | Riley County, KS (Manhattan, Fort Riley North, Ogden) (pop. 62,843) | 4.4 |
| 16. | Brazos County, TX (College Station, Bryan, South Brazos) (pop. 152,415) | 4.4 |
| 17. | Williamson County, TX (Round Rock, Georgetown, Cedar Park) (pop. 249,967) | 4.5 |
| 18. | Stafford County, VA (Aquia Harbour, Stafford Courthouse, Falmouth) (pop. 92,446) | 4.5 |
| 19. | Arlington County, VA (Arlington) (pop. 189,453) | 4.5 |
| 20. | Travis County, TX (Austin, Pflugerville, Wells Branch) (pop. 812,280) | 4.5 |
| 21. | Liberty County, GA (Hinesville, Walthourville, Midway) (pop. 61,610) | 4.6 |
| 22. | Hamilton County, IN (Fishers, Carmel, Noblesville) (pop. 182,740) | 4.6 |
| 23. | Carver County, MN (Chanhassen, Chaska, Waconia) (pop. 70,205) | 4.6 |
| 24. | Hidalgo County, TX (McAllen, Southeast Hidalgo, Edinburg) (pop. 569,463) | 4.7 |
| 25. | Johnson County, IA (Iowa City, Coralville, North Liberty) (pop. 111,006) | 4.7 |
| 26. | Howard County, MD (Columbia, Ellicott City, Scaggsville) (pop. 247,842) | 4.7 |
| 27. | Webb County, TX (Laredo, Bruni-Mirando, Webb) (pop. 193,117) | 4.7 |
| 28. | Davis County, UT (North Davis, South Davis, Layton) (pop. 238,994) | 4.7 |
| 29. | Wake County, NC (Raleigh, Cary, Apex) (pop. 627,846) | 4.8 |
| 30. | Paulding County, GA (Huntsville, Yorkville, Dallas) (pop. 81,678) | 4.9 |
| 31. | Sarpy County, NE (Bellevue, Papillion, La Vista) (pop. 122,595) | 4.9 |
| 32. | Hays County, TX (San Marcos, Kyle, Wimberley) (pop. 97,589) | 5.0 |
| 33. | Onslow County, NC (Jacksonville, Piney Green, Half Moon) (pop. 150,355) | 5.0 |
| 34. | Delaware County, OH (Delaware, Powell, Sunbury) (pop. 109,989) | 5.0 |
| 35. | Anchorage Municipality, AK (Anchorage) (pop. 260,283) | 5.0 |
| 36. | San Benito County, CA (Hollister, Aromas, Ridgemark) (pop. 53,234) | 5.0 |
| 37. | Anoka County, MN (Coon Rapids, Blaine, Fridley) (pop. 298,084) | 5.0 |
| 38. | Santa Clara County, CA (San Jose, Sunnyvale, Santa Clara) (pop. 1,682,585) | 5.1 |
| 39. | Sherburne County, MN (Elk River, Big Lake, Zimmerman) (pop. 64,417) | 5.1 |
| 40. | Williamson County, TN (Franklin, Brentwood, Boston) (pop. 126,638) | 5.1 |
| 41. | Alexandria city, VA (Alexandria) (pop. 128,283) | 5.2 |
| 42. | Coryell County, TX (Copperas Cove, Gatesville, Turnersville) (pop. 74,978) | 5.2 |
| 43. | Kings County, CA (Hanford, Lemoore, Avenal) (pop. 129,461) | 5.2 |
| 44. | Coconino County, AZ (Coconino, Flagstaff, Sedona) (pop. 116,320) | 5.2 |
| 45. | Matanuska-Susitna Borough, AK (Knik-Fairview, Lakes, Wasilla) (pop. 59,322) | 5.2 |
| 46. | Boulder County, CO (Boulder, Longmont, Lafayette) (pop. 291,288) | 5.3 |
| 47. | Wright County, MN (Buffalo, St. Michael, Monticello) (pop. 89,986) | 5.3 |
| 48. | Dakota County, MN (Eagan, Burnsville, Apple Valley) (pop. 355,904) | 5.3 |
| 49. | Clayton County, GA (Forest Park, Riverdale, Irondale) (pop. 236,517) | 5.3 |
| 50. | Cobb County, GA (Northeast Cobb, Marietta, Smyrna) (pop. 607,751) | 5.3 |
| 51. | Douglas County, KS (Lawrence, Eudora, Baldwin City) (pop. 99,962) | 5.4 |
| 52. | Gallatin County, MT (Bozeman, Belgrade, Gallatin Gateway) (pop. 67,831) | 5.4 |
| 53. | Imperial County, CA (El Centro, Calexico, Brawley) (pop. 142,361) | 5.4 |
| 54. | Washington County, MN (Woodbury, Cottage Grove, Oakdale) (pop. 201,130) | 5.4 |
| 55. | Story County, IA (Ames, Nevada, Story City) (pop. 79,981) | 5.4 |
| 56. | Cherokee County, GA (Woodstock, Lathemtown, Canton) (pop. 141,903) | 5.4 |
| 57. | Orange County, NC (Chapel Hill, Carrboro, Hillsborough) (pop. 118,227) | 5.4 |
| 58. | Kane County, IL (Aurora, Elgin, Carpentersville) (pop. 404,119) | 5.5 |
| 59. | Monterey County, CA (Salinas, Seaside, Monterey) (pop. 401,762) | 5.5 |
| 60. | Washington County, OR (Beaverton, Hillsboro, Somerset West-Rock Creek) (pop. 445,342) | 5.5 |
| 61. | Harris County, TX (Houston, Northwest Harris, Pasadena) (pop. 3,400,578) | 5.5 |
| 62. | Weld County, CO (Greeley, Windsor, Evans) (pop. 180,936) | 5.5 |
| 63. | Salt Lake County, UT (Salt Lake City, West Valley City, Sandy) (pop. 898,387) | 5.5 |
| 64. | Montgomery County, MD (Silver Spring, Wheaton-Glenmont, Germantown) (pop. 873,341) | 5.5 |
| 65. | Adams County, CO (Aurora, West Adams, Westminster) (pop. 363,857) | 5.6 |
| 66. | Mecklenburg County, NC (Charlotte, Huntersville, Matthews) (pop. 695,454) | 5.6 |
| 67. | Arapahoe County, CO (South Aurora, Southwest Arapahoe, Centennial) (pop. 487,967) | 5.7 |
| 68. | Clarke County, GA (Athens-Clarke County, Athens, Winterville) (pop. 101,489) | 5.7 |
| 69. | Will County, IL (Joliet, Bolingbrook, Homer Glen) (pop. 502,266) | 5.7 |
| 70. | Rutherford County, TN (Murfreesboro, Smyrna, La Vergne) (pop. 182,023) | 5.8 |
| 71. | York County, VA (Bethel Manor, Yorktown) (pop. 56,297) | 5.8 |
| 72. | Lake County, IL (Waukegan, North Chicago, Highland Park) (pop. 644,356) | 5.8 |
| 73. | Cameron County, TX (Brownsville, Harlingen, San Benito) (pop. 335,227) | 5.8 |
| 74. | Orange County, CA (North Coast, Santa Ana, Anaheim) (pop. 2,846,289) | 5.8 |
| 75. | Yolo County, CA (Davis, Woodland, East Yolo) (pop. 168,660) | 5.8 |
| 76. | Washtenaw County, MI (Ann Arbor, Ypsilanti, Saline) (pop. 322,895) | 5.8 |
| 77. | Cass County, ND (Fargo, West Fargo, Casselton) (pop. 123,138) | 5.8 |
| 78. | Union County, NC (Monroe, Indian Trail, Weddington) (pop. 123,677) | 5.8 |
| 79. | El Paso County, TX (El Paso, Socorro, San Elizario) (pop. 679,622) | 5.8 |
| 80. | Champaign County, IL (Champaign, Urbana, Rantoul) (pop. 179,669) | 5.8 |
| 81. | Orange County, FL (Orlando, Southwest Orange, Alafaya) (pop. 896,344) | 5.9 |
| 82. | Merced County, CA (Merced, Los Banos, Atwater) (pop. 210,554) | 5.9 |
| 83. | El Paso County, CO (Colorado Springs, Black Forest-Peyton, Security-Widefield) (pop. 516,929) | 5.9 |
| 84. | DeKalb County, GA (North Atlanta, Redan, Dunwoody) (pop. 665,865) | 5.9 |
| 85. | Boone County, MO (Columbia, Centralia, Ashland) (pop. 135,454) | 5.9 |
| 86. | Stearns County, MN (St. Cloud, Sartell, Waite Park) (pop. 133,166) | 5.9 |
| 87. | Spotsylvania County, VA (Spotsylvania Courthouse, Lake Wilderness) (pop. 90,395) | 5.9 |
| 88. | Los Angeles County, CA (Los Angeles, East San Gabriel Valley, Long Beach) (pop. 9,519,338) | 5.9 |
| 89. | Dane County, WI (Madison, Fitchburg, Sun Prairie) (pop. 426,526) | 5.9 |
| 90. | Starr County, TX (Roma-Los Saenz, Rio Grande City, Roma) (pop. 53,597) | 6.0 |
| 91. | Dallas County, TX (Dallas, Garland, Irving) (pop. 2,218,899) | 6.0 |
| 92. | Leon County, FL (Tallahassee, Northeast Leon, East Leon) (pop. 239,452) | 6.0 |
| 93. | Centre County, PA (State College, Park Forest Village, Bellefonte) (pop. 135,758) | 6.0 |
| 94. | San Bernardino County, CA (San Bernardino, Ontario, Fontana) (pop. 1,709,434) | 6.0 |
| 95. | Henry County, GA (Stockbridge, McDonough, Hampton) (pop. 119,341) | 6.0 |
| 96. | Charles County, MD (St. Charles, Waldorf, District 8, Bryantown) (pop. 120,546) | 6.0 |
| 97. | Montgomery County, VA (Blacksburg, Christiansburg, Merrimac) (pop. 83,629) | 6.0 |
| 98. | Larimer County, CO (Fort Collins, Loveland, Estes Park) (pop. 251,494) | 6.0 |
| 99. | Monroe County, IN (Bloomington, Ellettsville, Smithville-Sanders) (pop. 120,563) | 6.0 |
| 100. | Boone County, KY (Florence, Burlington, Hebron) (pop. 85,991) | 6.0 |
| 101. | Columbia County, GA (Martinez, Evans, Appling) (pop. 89,288) | 6.0 |