The US Geological Survey (USGS) has identified an estimated 2.3 million metric tons of undiscovered, economically recoverable lithium in the Appalachian region. This volume is equivalent to 328 years of US lithium imports based on 2025 levels.

The research indicates that these resources are located within pegmatites, which are large-grained rocks similar to granite.

“This research shows that the Appalachians contain enough lithium to help meet the nation’s growing needs – a major contribution to US mineral security, at a time when global lithium demand is rising rapidly,” said USGS Director Ned Mamula.

The findings divide the resource between two main areas, with the southern Appalachians holding an estimated 1.43 million metric tons of lithium oxide, primarily in the Carolinas.

The northern Appalachians contain approximately 900,000 metric tons, with the highest concentrations located in Maine and New Hampshire. Geologists utilized geochemical sampling, geophysical surveys, and tectonic history to reach these figures.

Could produce 1.6 million grid-scale batteries

According to the report, the total resource is sufficient to produce batteries for 130 million electric vehicles and 1.6 million grid-scale batteries. The USGS also estimates the lithium could support the production of 180 billion laptops, representing a 1,000-year supply at current demand levels, or 500 billion cellphones, which averages to 60 devices for every person on Earth.

Mamula noted that the findings provide a scientific basis for potential policy changes, permitting reforms, and workforce training. Although the United States was the leading lithium producer thirty years ago, it currently relies on imports for more than half of its annual consumption.

Lithium was included on the 2025 List of Critical Minerals because of its necessity in batteries for computers, military equipment, vehicles, and energy-grid storage. While Australia is the largest global producer, China is second and controls the majority of lithium refining and consumption. 

“The United States was the dominant world producer of lithium three decades ago, and this research highlights the abundant potential to reclaim our mineral independence,” Mamula asserted.

To address rising demand of lithium

The USGS projects that global production capacity will double by 2029 to address rising demand from technology companies.

The lithium-rich pegmatites in the Appalachian belt formed more than 250 million years ago during the creation of the supercontinent Pangea. High heat and pressure during mountain-building caused crustal rocks to melt into magmas with high lithium concentrations. 

“Pegmatites like the ones found in the Appalachian mountain belt are found in corresponding areas of Ireland and Portugal, both of which formerly bordered the Appalachians,” highlighted USGS.

The USGS notes that these estimates represent a 50 percent confidence level, meaning it is equally likely that the actual resource is higher or lower than the reported figures. In the northern Appalachians, there is a 10 percent probability that undiscovered resources could reach 7.4 million metric tons.

This assessment follows the mission established by the Energy Act of 2020, which requires the USGS to evaluate all domestic mineral resources.