In November 1997, a stratigraphic section of the Awatubi and Walcott Members of the Late Proterozoic Kwagunt Formation, Chuar Group, located in the Sixtymile Canyon area, of the eastern Grand Canyon National Park, Arizona, was measured, described and sampled. The goals of the study were: 1) to further characterize the petroleum source rock potential of the Awatubi and Walcott Members, previously concluded to constitute the significant source rock potential of the Chuar Group (Wiley, et al., 1998); 2) to add to the Chuar Group reference sample collection at the Arizona Geological Survey which is available for future study; 3) to integrate and synthesize Chuar Group source rock data from the Sixtymile Canyon section with that from the Nankoweap Canyon and Carbon Canyon sections (Wiley, et al., 1998); and 4) to review the range of possible organic-rich depositional environments and their characteristics to identify the most likely depositional environments for the Chuar Group. A total of 1480 ft (452 m) of section [653 ft (199 m) = Awatubi; 827 ft (252 m) = Walcott] was measured and 30 samples were collected (9 samples from the Awatubi Member, and 21 samples from the Walcott Member). All 30 samples were analyzed for total organic carbon (TOC) as a measure of organic richness and by Rock-Eval pyrolysis, which included Tmax as a measure of thermal maturity.