A model of oil shale compaction during retorting has been developed and incorporated into the one-dimensional retorting model. The model calculates the vertical stress distribution in a column of oil shale rubble and the degree of compaction that these stresses cause. A correlation has been developed that relates shale grade, initial void volume, and vertical stress to the final compaction of the shale bed. The model then determines the gas pressure drop and its effects through the retort. Results of experiments on the decomposition of kerogen in the interim eastern reference oil shale indicate that kerogen and produced bitumen are converted to oil, gas, and residue simultaneously. Hence, the oil production cannot be expressed well in a first-order equation. Comparison of bitumen production from western oil shale, which is highly aliphatic, to that from the more aromatic eastern shale indicates that the formation of bitumen may be a function of oil shale aromaticity. Several samples produced by the recycled hot oil pyrolysis of tar sand were analyzed. Detailed gas chromatography/mass spectrometry analyses were used to evaluate the potential of the pyrolysis product oil as a feedstock for high-density fuel production. The products from the current production conditions were not felt to be suitable. A series of UCG experiments in large coal blocks demonstrated successful gasification of Illinois No. 6 bituminous coal at ash slagging conditions using a borehole link. Gasification conditions for the Rocky Mountain No. 1 field test were tested in a large block of Hanna coal.