Measurements have been made on the chemical and physical properties of two oil shales designated as interim reference oil shales by the Department of Energy. One oil shale is a Green River Formation, Parachute Creek Member, Mahogany Zone Colorado oil shale from the Anvil Points mine and the other is a Clegg Creek Member, New Albany shale from Kentucky. Material balance Fischer assays, kerogen concentrates, carbon aromaticities, thermal properties, and bulk mineralogic properties have been determined for the oil shales. The measured properties of the interim reference shales are comparable to results obtained from previous studies on similar shales. The western interim reference shale has a low carbon aromaticity, high Fischer assay conversion to oil, and a dominant carbonate mineralogy. The eastern interim reference shale has a high carbon aromaticity, low Fischer assay conversion to oil, and a dominant silicate mineralogy. Chemical and physical properties, including ASTM distillations, have been determined for shale oils produced from the interim reference shales. The distillation data were used in conjunction with API correlations to calculate a large number of shale oil properties that are required for computer models such as ASPEN. The experimental determination of many of the shale oil properties was beyond the scope of this study. Therefore, direct comparison between calculated and measured values of many properties could not be made. However, molecular weights of the shale oils were measured. In this case, there was poor agreement between measured molecular weights and those calculated from API and other published correlations. 23 refs., 12 figs., 15 tabs.