Rock Island County is named after an island in the Mississippi River known as Rock Island. It is the only county in Illinois named after an island.

          The county seat for Rock Island is in the city of Rock Island, IL 61201.

          It has a long list of cities including Illinois City, Edgington, Buffalo Prairie, Taylor Ridge. Rock Island is actually home to about 22 cities and towns.

          The Mississippi River forms Rock Islands Western border. Also the Rock River flows through Rock Island along with the Copperas River.