This paper describes the recovery of oil from eastern oil shales using modifications of the supercritical extraction techniques that were successful in recovering 90 weight percent of the oil from Green River oil shale. In the case of eastern shales as much as 92 weight percent of the oil in the shale was recovered as a liquid product using tetralin and water at a temperature of 400 degrees C. The chemical composition of the oil extracted from a Chattanooga shale is presented. Changes in composition of minerals under supercritical fluid extraction conditions are discussed and related to the overall recovery process.