May 4, 2026: The US has estimated reserves of economically recoverable lithium to replace more than 300 years of imports at last year’s level, according to latest research.
The US Geological Society revealed on April 28 that the Appalachian region of the eastern US contains an estimated 2.3 million tonnes of undiscovered lithium.
The southern Appalachians hold an estimated 1.43 million tonnes of lithium oxide, concentrated in the Carolinas, and the northern Appalachians hold an estimated 900,000 tonnes, concentrated in Maine and New Hampshire, according to estimates in a new USGS scientific paper published in Natural Resources Research.
USGS said the lithium is present in pegmatites, large-grained rocks similar to granite.
The announcement comes just six months after Batteries International reported USGS had started airborne surveys over portions of the Blue Mountains in California and adjacent areas to identify potential sites for the recovery of critical minerals essential to battery manufacturing and other industries.
According to the USGS, the estimated 2.3 million tonnes of lithium oxide in the Appalachian region would be enough lithium for batteries in 1.6 million grid-scale batteries – large enough to stabilise an electric grid and 130 million EVs.
A team of USGS geologists worked together on the northern and southern assessments, combining geologic maps, tectonic history, geochemical sampling, geophysical surveys, and records of mineral occurrences.
They then conducted simulations using a global dataset for lithium pegmatites to estimate how many undiscovered lithium deposits there are in the study area, and how much lithium they hold.
USGS said details from the southern assessment covering the Appalachians from Maryland to Alabama will be published later.
The findings come as USGS projects that world production capacity for lithium will double by 2029, driven by increasing demand.
Ned Mamula, USGS director, said: “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.
The US was the dominant world producer of lithium three decades ago and this research highlights the abundant potential to reclaim our mineral independence.”
In 2022, the USGS added lithium to the list of mineral commodities critical to the US economy and national security. Lead was added to the list last year.
