2.3M tons of lithium found in Appalachia

May 01, 2026

The U.S. Geological Survey (USGS) has revealed a substantial untapped lithium reserve in the Appalachian region, estimating approximately 2.3 million metric tons of economically recoverable resources yet to be discovered. Based on projected 2025 import levels, this amount could supply the United States with lithium for more than three centuries.

According to the study, these lithium deposits are primarily found in pegmatites—coarse-grained igneous rocks closely related to granite, known for hosting valuable minerals.

USGS Director Ned Mamula emphasized the strategic importance of the discovery, noting that the Appalachian region could play a key role in strengthening domestic mineral security amid surging global demand for lithium.

Major lithium deposits identified in Appalachia

The report divides the estimated resources between two key regions:

• Southern Appalachians: 1.43 million metric tons of lithium oxide, concentrated mainly in the Carolinas.

• Northern Appalachians: Roughly 900,000 metric tons, with the richest deposits located in Maine and New Hampshire.

Researchers reached these conclusions through a combination of geochemical analysis, geophysical mapping, and studies of the region’s tectonic evolution.

Potential to power millions of batteries

The USGS findings suggest that these lithium reserves could have massive industrial applications. The total resource could support the production of:

• Batteries for approximately 130 million electric vehicles

• Around 1.6 million grid-scale energy storage systems

• Up to 180 billion laptops, representing a millennium of supply at current usage rates

• Nearly 500 billion smartphones, equivalent to about 60 devices per person globally

Mamula highlighted that these insights could inform future policy decisions, including permitting reforms and workforce development initiatives. While the U.S. was once the world’s leading lithium producer three decades ago, it now depends on imports for over half of its annual consumption.

Lithium’s role as a critical mineral

Lithium was officially added to the 2025 Critical Minerals List due to its essential role in manufacturing batteries used in electronics, defense systems, electric vehicles, and renewable energy storage.

Globally, Australia remains the top lithium producer, followed by China, which dominates refining and consumption capacity.

Mamula stated that the study underscores the opportunity for the United States to regain leadership in lithium production and reduce reliance on foreign supply chains.

Rising demand and future supply outlook

The USGS forecasts that global lithium production capacity could double by 2029 as demand accelerates, particularly from the technology and clean energy sectors.

The lithium-rich pegmatites in the Appalachian Mountains formed over 250 million years ago during the assembly of the supercontinent Pangea. Intense heat and pressure during this period caused crustal rocks to melt, forming lithium-enriched magmas.

Interestingly, similar geological formations can be found in regions such as Ireland and Portugal, which were once geologically connected to the Appalachian belt.

Resource uncertainty and future exploration

The USGS notes that the current estimates carry a 50% confidence level, meaning actual resources could be either higher or lower. In the northern Appalachians alone, there is a 10% probability that undiscovered lithium resources could reach as much as 7.4 million metric tons.

This assessment aligns with the mandate established under the Energy Act of 2020, which directs the USGS to evaluate domestic mineral resources to enhance national supply security.