The Smackover Formation in southwestern Arkansas could contain millions of tons of lithium, according to a recent report by the U.S. Geological Survey (USGS) and Arkansas Department of Energy and Environment. The lithium deposits estimated in this geological area represent between 35% and 136% of the current estimated lithium resources in the United States. According to the study, lithium brines in the Smackover Formation may hold between 5.1 million and 19 million tons of lithium.