NPR | USGS Announces Largest Oil And Gas Deposit Ever Assessed In US NPR The U.S. Geological Survey says a deposit in West Texas is the largest continuous oil and gas deposit ever discovered in the United States. On Tuesday, the USGS announced that an area known as the Wolfcamp shale contains 20 billion barrels of oil and ... USGS: Largest oil deposit ever found in US discovered in Texas There's oil in them thar flatlands: Report puts a massive number on West Texas shale formation Largest US oil and gas discovery made - USGS |