Abstract Six potential trapping plays in northwestern Ohio are recognized in the Trenton Limestone reservoir of the Lima-Indiana Field and surrounding areas. The six plays are: 1) simple anticlinal traps, 2) faulted anticlines, 3) updip facies change, 4) dolomitization along fracture trends, 5) porosity-permeability traps and 6) small anticlinal noses. Limited production records suggest that fracture-enhanced plays are the most productive of oil and gas.