A U.S. Geological Survey-led study, in collaboration with the Arkansas Department of Energy and Environment, has estimated that the Smackover Formation in southwestern Arkansas contains between 5 to 19 million tons of lithium, which could meet global demand for car batteries in 2030 nine times over. This discovery, made using a combination of water testing and machine learning, highlights the potential for the U.S. to lessen its reliance on lithium imports and bolster supply chain resilience. The Smackover Formation, a relic of an ancient sea, stretches across several Southern U.S. states and has traditionally been associated with oil and gas production. The lithium is found in brines co-produced during these operations, presenting an opportunity to transform waste into a valuable resource. While the potential economic and environmental benefits are significant, the study cautions that further technological advancements are needed to assess the commercial viability of extracting lithium from these brines. Companies like ExxonMobil are already exploring ways to exploit these reserves using new technologies such as Direct Lithium Extraction (DLE).