Utah-Arizona Overthrust-Hingeline Belt

Part of the Rocky Mountain orogenic complex, the Overthrust-Hingeline Belt runs from Alaska's Brooks Range, along the Rockies through Canada and the US, through Mexico into Central America. Although often used interchangeably, the terms Overthrust Belt and Hingeline actually refer to very different geologic phenomena: The Hingeline is depositional in nature, while the Overthrust Belt resulted from violent stresses associated with compressional deformation. Optimistic geologists estimate that the Montana-to-Arizona area of the belt could produce more than 15 billion bbl of oil and 100 trillion CF of gas, which would exceed Prudhoe Bay's proved reserves, but drilling costs in the area are high and conservationists have targeted much of the land for wilderness preserves.