The USGS Central Region Energy Team assessed the oil and gas resources of the United States. Cell maps for each oil and gas production area were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution of production in a play. Each cell represents a one-mile square of the land surface, and the cells are coded to represent whether the wells included within the cell are predominantly oil-producing, gas-producing, or dry. The well information was initially retrieved from the Petroleum Information Well History Control System (WHCS), which is a proprietary, commercial database containing information for most oil and gas wells in the U.S. Cells were developed as a graphic solution to overcome the problem of displaying proprietary WHCS data. No proprietary data are displayed or included in the cell maps. The data used to generate the cells are from WHCS and are current as of December, 1990. This version of the dataset was published as part of the USGS Global GIS : global coverage database (2003). The USGS Global GIS database contains a wealth of USGS and other public domain data, including global coverages of elevation, landcover, seismicity, and resources of minerals and energy at a nominal scale of 1:1 million. The U.S. Geological Survey (USGS) and The American Geological Institute (AGI) announced a cooperative agreement that will focus on making the USGS Global Geographic Information System (GIS) database readily available to educators and the general public in the form of a DVD based world atlas.