NPR | USGS Announces Its Largest Oil And Gas Discovery Ever NPR 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 ... The largest oil deposit ever found in America was just discovered in Texas 'Largest' Shale Oil Reserve Discovered in US Permian's Wolfcamp formation called biggest shale oil field in US |