From 1973 to 1976, the Paraho Oil Shale Demonstration, a 3-years, $10 million research program, privately sponsored by 17 participants, was carried out to demonstrate the operability of the Paraho technology in retorting oil shale. Retorting operations were carried out in Direct Heated, Indirect Heated, and Combination Modes. Because of the research nature of that earlier program, there was practically no environmental monitoring of the paraho operations. The environmental monitoring carried out during that time was preformed to obtain some qualitative information or to define valid sampling, preparation, and analytical procedures useful in assessing oil shale retorting operations.