Hi, @llundgren – Good questions. I know @alycia-stigall’s Atlas of Ordovician Life has some stratigraphic information on it for each of the species found in the Cincinnati region. Here is a link to the Trilobite section: http://www.ordovicianatlas.org/atlas/arthropoda/trilobita/
I can’t think of anything else off the top of my head but I think this is another good trilobite reference: http://trilobites.info/ It doesn’t have specific formations but it has an insane amount of good figures and details specifics of a variety of trilobites.
The Paleobiology Database (fossilworks.org) may be a good source to figure out what is found in the same horizons… So, using Flexicalymene meeki as a test here are the results: http://fossilworks.org/bridge.pl from this you can click any of the locations where F. meeki is found and get a list of other taxa reported from the same horizon (e.g., Ontario). It’s all text, nothing really visual but lots of data.
In summary, I have nothing that is exactly what you want but the above sites are what I would use to find the results… although they are visually unappealing in fossilworks/PBDB. =[