| Description: | Putnam County, located in central Illinois, covers an area of 160 square miles and had a 2003 population of 6,119 according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Putnam County was the smallest county in Illinois geographically, but 5th smallest in terms of population. Combining these two measures, Putnam County had the 37th lowest population density per square mile among Illinois 102 counties. | |