This Raw Data File provides lithologic descriptions of core fragments recovered from a series of core holes drilled by Exxon (mid-80s) in the uplands bordering the Yukon Flats basin. In addition to descriptions of the material, the tabulated file includes geographic location, core hole numbers, an age estimate, core fragment depth, general lithology, grain size, and facies interpretation. The author examined these core materials in Fairbanks during winter and spring 2002. This work was done in preparation for an assessment carried out by the U.S. Geological Survey of undiscovered, technically recoverable hydrocarbon resources in the Yukon Flats basin.