 saint clair is a city in franklin county, missouri, united states. the population was 4,472 at the 2010 census.http://www.city-data.com/city/st.-clair-missouri.html ==geography== saint clair is located at  (38.349654, -90.982812). according to the united states census bureau, the city has a total area of , of which,  is land and  is water. == history =
1859_establishments_in_the_United_States Cities_in_Franklin_County,_Missouri Communities_on_U.S._Route_66