| Description: | Bureau County, located in northern Illinois, covers an area of 868 square miles and had a 2003 population of 35,221, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Bureau County was the 94th smallest county in Illinois geographically, but 59th smallest in terms of population. Combining these two measures, Bureau County had the 40th smallest population density per square mile among Illinois 102 counties. | |