This project was undertaken to evaluate the heavy-oil (oil less than 25/sup 0/ API) potential of northeastern Oklahoma - specifically, northwestern Ottawa and northeastern Craig Counties, the area considered to have the best possibility for shallow, heavy-oil accumulations. Although previous reports indicated that potential resources of the entire region possibly amounted to billions of barrels of oil in place, a detailed subsurface investigation of the Oklahoma study area, including an 18-hole drilling and coring program, has shown that insignificant quantities of heavy oil are present in discontinuous Middle Pennsylvanian sandstones of varying permeability. 2 tables, 9 figures.