Summary Report #4 and Quarterly Data Report #4 cover the fourth quarter of exploration and environmental data for the first year of the environmental Baseline program for Tract C-b. These reports specifically cover the summer quarter of June, 1975 through August, 1975. Quarterly Data Report #4 consists of four volumes of a comprehensive compilation of data submitted to the Area Oil Shale Supervisor in Grand Junction on October 15, 1975. Parties interested in reviewing the comprehensive data may contact the Area Oil Shale Supervisor's Office. This Summary Report #4 is intended to provide the reader with a general overview and initiate the interpretation of the information included in the Quarterly Data Report #4. For a complete summary of on-Tract activities to date, reports from all four quarters must be consulted.