Cumulative production is the amount of oil, natural gas, or natural gas liquids produced from the oil and gas fields in each province assessed by the U.S. Geological Survey. Remaining reserves constitute the sum of proved plus probable reserves of oil, gas, or natural gas liquids present in oil and gas fields within each province. These volumes are from the proprietary Petroconsultants database, current through 1995, (Petroconsultants, 1996) and are presented here with permission. The mean values of undiscovered oil, natural gas, and natural gas liquids amounts presented here are aggregated at the geologic province level (U.S. Geological Survey Assessment Team, 2000). Definitions of oil, natural gas, and natural gas liquids are those used in the World Petroleum Assessment, 2000. Petroleum is considered to include oil, natural gas, and natural gas liquids, and is reported on a barrel of oil equivalents (BOE) basis, where 6000 cubic feet of gas equals one barrel equivalent. Oil and natural gas liquids resources are reported in millions of barrels (MMBO and MMBNGL). Natural gas is reported in billions of cubic feet of gas (BCFG).