An industrial hygiene survey of the Paraho Oil Shale Mining and Processing Facility in Anvil Points near Rifle, Colorado, was performed on August 6-7, 1975. This survey consisted of an investigation of the underground operations for diesel emission contaminants and of the aboveground work areas for all inhalation contaminants other than silica dust NO2, no, h2so4, formaldehyde, co2, so2, and carbon monoxide. None of the determinations of contaminants in the underground operations indicate air concentrations exceeding their standards. The results of the samples collected aboveground indicate only one welding operation where the employee's exposure exceeds the standards because of excessive total dust and lead. Since the survey, the employer has installed an exhaust ventilation system that has significantly reduced the welder's exposure.