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Critical minerals developer 3 Proton Lithium (3PL) has identified what could become the largest known tungsten deposit in the United States at its Railroad Valley Minerals project in eastern Nevada. According to the company’s latest resource assessment, the project contains an inferred tungsten resource of 1.78 million tonnes.

If future technical and economic studies confirm the deposit can be mined profitably, it would exceed the country’s next largest known tungsten resource by more than five times. The estimate excludes a section of the property where exploration activities remain prohibited, leaving additional mineral potential untested.

The company estimates the in situ value of the identified tungsten resource at approximately US$152 billion based on current tungsten prices.

NASA Land Withdrawal Limits Exploration

Exploration is blocked on roughly one-third of the claim package due to a federal land withdrawal approved in 2023.

The Bureau of Land Management removed approximately 17 square miles from mineral exploration and mining following a request from NASA. The agency uses the flat desert terrain as a calibration site for satellite instruments, where spacecraft signals are received, and measurement data are verified. NASA has maintained that mining within the protected area would interfere with those activities.

Because drilling has not been permitted within the withdrawn ground, the current resource estimate does not include any tungsten that may exist beneath that portion of the property.

Domestic Supply Carries Strategic Significance

The United States relies on imported tungsten after domestic mining ceased about a decade ago. China produces roughly 80% of the world’s tungsten, giving it substantial influence over supplies of the metal, which is commonly used in ammunition, aerospace components, industrial cutting tools, and high-temperature manufacturing applications.

Chinese export controls have tightened the global supply of tungsten, pushing prices up nearly 600% since early 2025. The price increase has renewed attention on domestic projects capable of supplying tungsten to US manufacturers and defence contractors.

Federal Policy Places Focus on Critical Minerals

The Railroad Valley Minerals project is part of the US government’s FAST-41 permitting program, a federal initiative to streamline environmental reviews and improve coordination between agencies responsible for approving major infrastructure and critical minerals projects.

At the same time, the government is considering providing up to US$1.6 billion in financial support for a planned tungsten mine in Kazakhstan as part of its effort to reduce dependence on Chinese tungsten supplies.

3PL is seeking to reverse the land withdrawal affecting its Nevada property to gain access to the restricted acreage for additional exploration and to advance a potential major domestic tungsten source.

Commercial Production Remains Years Away

3PL’s Railroad Valley Minerals project remains in the early stages of development, with additional drilling, engineering studies, environmental reviews, and permitting still needed before any construction decision can be made.

Access to the restricted portion of the claim package would also need to be resolved before the full extent of tungsten mineralization can be evaluated.

Commercial production is expected to remain at least five years away if the project secures regulatory approvals and access to the withdrawn ground.