Laboratory studies to evaluate the use of electricity for fracturing various grades of Colorado oil shale were started in 1964. Breakdown voltage requirements ranged up to several thousand volts and varied widely from one grade of shale to another. With few exceptions, the shale samples were readily fractured at relatively low current levels. Experiments were expanded to a small-scale field project in an abandoned oil-shale mine tunnel. The purpose was to study electrical characteristics of oil shale when subjected to overburden pressure. In general, these tests confirmed the laboratory experiments. Fracturing was accomplished at all electrode spacings used. The spacings varied from 3 to 129 ft. Fracturing tests also were conducted in 4 shallow wells drilled in the oil-shale formation. Some new permeable zones were created but, in general, the induced permeability between wells was not up to desired levels.