Biologic markers, compounds derived essentially unchanged from living organisms, have been used by petroleum geologists to relate oils to their original source rock material. This technique is based on the ubiquitous nature of biomarkers in ancient sediments and on the characteristic way in which ratios of biomarkers vary from location to location. Biomarker derivatives from kerogen, the insoluble organic portion of oil shale, have been determined by a variety of methods and compared to their bitumen analogs. In this work, oils from cores have been prepared in varying locations in the Green River Formation in order to compare biomarker ratio characteristics that correlate across the resource, as well as the factors that distinguish one location from another. 22 references.