The U.S. Geological Survey says it has found the largest continuous oil and gas deposit ever discovered in the United States. On Tuesday, the USGS announced that a swath of West Texas known as the Wolfcamp shale contains 20 billion barrels of oil and 16 trillion cubic feet of natural gas. That is nearly three times more petroleum than the agency found in North Dakota's Bakken shale in 2013. As NPR's Jeff Brady reported, the amount of oil in the Wolfcamp shale formation is nearly three times the amount of petroleum products used by the entire country in a year....