Round Top Project

Heavy- and light-rare-earth, lithium, gallium and beryllium deposit at Round Top Mountain in Hudspeth County, West Texas, held through the Round Top Mountain Development (RTMD) joint venture in which USA Rare Earth held 81.3% and Texas Mineral Resources Corp. (TMRC) 18.7% at December 31, 2025. Under Item 1300 of Regulation S-K the property is an exploration-stage property with no disclosed mineral reserves and no declared S-K 1300 mineral resources. The deposit is a rhyolite-hosted, above-ground body amenable to a low-complexity flowsheet of mining, crushing, heap leaching and solvent extraction, which is expected to reduce capital intensity, energy use and operational footprint relative to conventional mining; the arid, sparsely populated setting further limits environmental impact. Historical exploration by TMRC (2010-2019) included 173 located drill holes, 80 reverse-circulation and 2 core holes drilled and 3,081 samples analyzed. The Company expects to complete a definitive feasibility study by early 2027 and move into commercial production by late 2028. A Colorado (Wheat Ridge) facility supports separation and process development. On March 4, 2026 USA Rare Earth signed a definitive merger agreement to acquire the TMRC minority and become the sole operator and 100% economic beneficiary of the project.