Chert map - Missouri

[Missouri Mule]

Is there what I believe is called a "chert exposure map" available for the State of Missouri?  Perhaps, I have the wrong name, but I have been trying to find a map that names and shows the location sites of the various chert formations of Missouri.  Some of the artifact pictures I have seen are quite striking (pardon the pun), which has further my interest in the subject. Thanks

[painshill]

Hi Thomas
The USGS does a fine job in making geological maps available on-line for free. They are downloadable (although huge) but formatted as a “shapefile” or other data formats which need specialized software to read. Better to use the interactive versions. You can’t really download or print a “Missouri” map – you have to select an area you are interested in and check (or print) a bit at a time. You can do it here:

http://mrdata.usgs.gov/sgmc/mo.html

Hold down the shift key while dragging the mouse to select an area you want magnified.
NB: Below the map, click on the link “Legend for the lithology shown on the map” and print that out for reference. But watch out – the blue/greenish grey colour for chert is very similar to colours used for other rocks. If you're in doubt about what colour you're looking at, then clicking on the location on the enlarged map brings up the details of the geological formation.
I spent an idle couple of minutes Googling "Missouri Chert Quarries" and variants around that. There are loads and loads of resources giving directions to locations with local maps for hiking and cycling trails through localities where there was a whole load of flaking going on. I'm jealous. Happy hunting.