| Description: | Iroquois County, located in east central Illinois, encompasses a 1,117 square mile area and had a 2003 population of 30,684, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Iroquois County was the 3rd largest county in Illinois geographically, but 49th largest in terms of population. Combining these two measures, Iroquois County had the 16th lowest population density per square mile among Illinois 102 counties. | |