This is a map showing St. Louis Metro-East, 5 Illinois counties of the St. Louis MSA as described by the 2000 census. Clinton, Jersey, Madison, Monroe and St. Clair counties per http://lmi.ides.state.il.us/lmr/metroeast.htm
Own work
Own work derived from  David Benbennick's map.  For more information, see Commons:United States county locator maps.