| | Description: | Piatt County, located in central Illinois, covers an area of 440 square miles and had a 2003 population of 16,426, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Piatt County was the 64th largest county in Illinois geographically, but 32nd smallest in terms of population. Combining these two measures, Piatt County had the 33rd lowest population density per square mile among Illinois 102 counties. | |
