The United States has about 54 billion barrels of bitumen in numerous tar sand deposits. However, only about 10 to 15% of the bitumen can be recovered by conventional, surface mining techniques. This implies that the remainder will have to be recovered by in situ, thermal recovery processes. For these in situ processes to be operated efficiently, numerous chemical and physical parameters of the produced gas, oil, and water need to be determined and monitored. The parameters of the produced oil need to be compared with the parameters of the original bitumen to determine the extent of the former's thermal alteration. Only by understanding the interrelationships among these parameters and process variables can the process be understood and, therefore, controlled. This report contains listings of those parameters for gas, oil and original bitumen, and water that have been determined to be of value in monitoring and evaluating thermal recovery processes in tar sand. In addition, the application of laboratory- and field-derived data to the interpretation of processes is also discussed. In general, these data show definitive correlations between the study parameters and production progress.