| Description: | DuPage County, located in northeastern Illinois, covers an area of 334 square miles and had a 2003 population of 925,188, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, DuPage County was the 16th smallest county in Illinois geographically, but 2nd largest in terms of population. Combining these two measures, DuPage County had the 2nd highest population density per square mile among Illinois 102 counties. | |