Recently, increased oil and gas production from the Clinton sandstone has prompted a search for, and evaluation of, additional Clinton prospects in northeastern Ohio. Geologic investigations show that hydrocarbons are trapped in the channels and bars of small deltas, at depths of 4,000-5,300 ft (1,200-1,600 m). Accumulation is controlled stratigraphically. Structure is of negligible importance except in segregation of oil and gas within reservoirs. Reservoir conditions are poor; the porosity and permeability generally are less than 12 percent and 2 md, respectively. Evaporites in the sandstone complicate exploration. The areal distribution and extent of commercial reservoirs are very erratic and limited. Primary reserves, with solution-gas drive, are not expected to excee 60 bbl of oil or 250 Mcf of gas per acre-foot. A very few scattered wells may recover more. Commercial success depends on an unlimited market and a premium price.