| | Description: | Winnebago County, located in northern Illinois, covers an area of 514 square miles and had a 2003 population of 284,313, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Winnebago County was the 51st largest county in Illinois geographically, but 7th largest in terms of population. Combining these two measures, Winnebago County had the 6th highest population density per square mile among Illinois 102 counties. | |
