The U.S. Department of Energy (DOE) has instituted a basin-analysis study to encourage drilling by independent oil companies within the continental United States. The work is being performed at the National Institute for Petroleum and Energy Research (NIPER) by BDM Oklahoma, the manager of the facility for DOE. The Black Mesa region in northeastern Arizona (Figure 1-1) was selected by DOE for the initial NIPER-BDM Exploration and Drilling Group survey to develop prospects in unexplored/underexplored basins in the lower 48 states. The Black Mesa Basin is significantly underexplored, with only six wells having been drilled in the deep, central portion of the basin on the 1.5 million-ac Hopi Reservation, and an additional six wells on the flanks of the area. The Hopi wells were all drilled during 1965, and none had any follow-up testing or subsequent offsets. The study area includes the topographic Black Mesa (the site of the ancestral Hopi lands) and the geologically contiguous surrounding potential reservoirs beneath the southwestern parts of the Colorado Plateau. Much of this latter area underlies Navajo tribal lands.