St. Louis County county located in the U.S. state of Missouri. According to the 2000 census, the population was 1,016,315, making the county the most populous in the state of Missouri. This county is notable for its 400+ private-street associations. Its county seat is Clayton 6 . St. Louis County is part of the sprawling St. Louis Metro Area wherein the independent City of St. Louis and its suburbs in St. Louis County, as well as the surrounding counties in both Missouri and Illinois all together account for a total population of over 3 million people. St. Louis County borders the City of St. Louis, which is independent from St. Louis County. The 2006 estimate for the county is 1,000,510.http://factfinder.census.gov/servlet/ACSSAFFFacts?_event=ChangeGeoContext&geo_id=05000US29189&_geoContext=&_street=&_county=St.+Louis&_cityTown=St.+Louis&_state=04000US29&_zip=&_lang=en&_sse=on&ActiveGeoDiv=&_useEV=&pctxt=fph&pgsl=010&_submenuId=factsheet_1&ds_name=ACS_2006_SAFF&_ci_nbr=null&qr_name=null®=null%3Anull&_keyword=&_industry=
