Oneota Dolomite  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Ordovician
 ....Lower Ordovician
 .....Oneota Dolomite
RTIowa
 Illinois
 Indiana
 Wisconsin
 Minnesota
 Michigan
 Prairie du Chien Group
SNIn Prairie du Chien Group. NW Illinois, Indiana, NW Iowa, Michigan, S Minnesota, and SW Wisconsin. Added to Thesaurus in 1995.