Chart of Clayton County, Iowa communities by population (2010)

† county seat

Reference 1: Population (2010 Census).

Reference 2: Postville (partially in Allamakee County), Guttenberg, Monona, Strawberry Point, † Elkader, McGregor, Edgewood (partially in Delaware County), Garnavillo, Marquette, Farmersburg, Luana, Volga, North Buena Vista, St. Olaf, Garber, Osterdock, Clayton, Elkport and Millville.

Source: http://en.wikipedia.org/wiki/Clayton_County,_Iowa