Oil Shale is found in many places in the world. 

Commercial production of shale oil is occurring in Estonia, China and Brazil.  Demonstration scale oil shale plants have been operated in the United States, but none are active at this time.  However, experimental scale activities are currently under way in Colorado and Utah to test new and innovative technologies that are expected to be environmentally acceptable, economic and sustainable. 

"The largest known oil shale deposits in the world are in the Green River Formation, which covers portions of Colorado, Utah, and Wyoming.  Estimates of the oil resource in place within the Green River Formation range from 1.5 to 1.8 trillion barrels.  Not all resources are recoverable.  For potentially recoverable oil shale resources, we roughly derive an upper bound of 1.1 trillion barrels of oil to a lower bound of about 500 billion barrels." [Bartis, James T. etal, Rand Corporation, Oil shale Development in the United States, ISBN: 0-8330-3848-6, 2005]  This is an amount of shale oil that is comparable with the conventional oil reserves in the Middle East.