"The Laramie e Energy Technology Center has conducted several in situ recovery projects in the Northwest Asphalt Ridge (Utah) tar sand deposit. Briefly, the design, conduct, and engineering results are presented for two of these projects (a reverse/forward combustion project and a steamflood project). In more detail, the chemical and physical properties of the produced oils are discussed, and the properties of the produced oils are compared with each other and with the original bitumen. It is concluded that the oil produced by the reverse/ forward combustion project is significantly improved in fuel quality with respect to the original bitumen. However. the oil produced by the steamflood project is very similar to the original bitumen."