The Round Top rare earth project in Hudspeth County, west Texas, is the most advanced heavy rare earth development in the United States — a 1.6-billion-tonne rhyolite deposit carrying 16 of the 17 rare earth elements, with heavy rare earths (HREEs) accounting for roughly 70% of the total mix. Under an Accelerated Mining Plan, operator USA Rare Earth (Nasdaq: USAR) is targeting commercial production in 2028 and feedstock extraction of 40,000 metric tonnes per day by 2030.
Round Top Rare Earth: Location and Ownership
Round Top Mountain sits approximately 85 miles southeast of El Paso in Sierra Blanca, Hudspeth County, Texas. The site is located entirely on Texas state land, operated under a long-term lease with the Texas General Land Office. Lease proceeds support the Texas Permanent School Fund, bypassing federal Bureau of Land Management jurisdiction entirely.
USA Rare Earth, Inc. (Nasdaq: USAR) is the sole operator and, subject to closing, will become the 100% economic beneficiary of Round Top. In March 2026, USAR announced a definitive agreement to acquire Texas Mineral Resources Corp. (OTCQB: TMRC) — which held an 18.6% interest in the project — in an all-stock transaction valued at approximately $73 million (3,823,328 USAR shares at the March 4, 2026 closing price). The deal is expected to close by Q3 2026, pending TMRC shareholder approval. USAR previously held the majority economic interest through a development and funding agreement dating to 2018.
The project also holds a long-term lease covering approximately 950 acres at Round Top, with prospecting rights on an additional 9,345 acres of adjacent Texas state land.
Geology: Why Round Top Matters for Heavy Rare Earths
Round Top Mountain is a rhyolite laccolith — a mushroom-shaped igneous intrusion roughly 2 kilometres in diameter and over 375 metres high. The Texas Bureau of Economic Geology has estimated the mass of the rhyolite at approximately 1.6 billion tonnes. The deposit hosts 16 of the 17 rare earth elements, with heavy rare earths including dysprosium and terbium accounting for roughly 70% of the total REE content — the inverse of most rare earth deposits, which are dominated by light rare earths.
REE mineralisation occurs in microcrystals of yttrofluorite, disseminated consistently throughout the rhyolite. This geological consistency is operationally significant: grade does not vary materially with depth or location across the drilled portion of the mountain, allowing processing parameters to be optimised early and held stable for the life of the mine.
Beyond rare earths, Round Top hosts near-surface concentrations of lithium, gallium, beryllium, hafnium, and zirconium — co-products that contribute to project economics and place it among the most mineralogically diverse critical mineral deposits in North America. According to USAR, Round Top contains concentrations from nearly half the minerals on the US Critical Minerals List.
Mining Method: Open Pit and Heap Leach
Round Top is designed as an open-pit operation with a heap leach processing circuit. Ore will be crushed and stacked on a lined containment pad, where a dilute acid solution separates target elements into a liquid leachate. Laboratory and pilot-scale test work has returned recovery rates above 85% for key HREEs.
The crushed rhyolite requires minimal waste rock stripping due to the consistent, disseminated nature of the mineralisation — a cost advantage relative to conventional hard-rock rare earth deposits. Under the Accelerated Mining Plan, the operation targets extraction of approximately 40,000 metric tonnes per day of feedstock by 2030.
Leachate from Round Top will feed into USAR’s hydrometallurgical processing chain. The company is commissioning a demonstration facility in Wheat Ridge, Colorado in Q2 2026, which will run continuous demonstrations of the Round Top flowsheet and mixed rare earth carbonate separation, with data expected to underpin commercial engineering through to the end of 2026. Vat leaching at the Round Top site itself commenced in Q1 2026, supplying feedstock to the Colorado facility.
Development Timeline and Feasibility Studies
In January 2026, USAR appointed Fluor Corporation and WSP Global as Engineering, Procurement and Construction Management (EPCM) partners for Round Top. Fluor and WSP are leading the feasibility programme alongside geotechnical and confirmatory drilling initiated in early 2026.
| Milestone | Target |
|---|---|
| PFS (Preliminary Feasibility Study) | Q3 2026 |
| Colorado hydromet demo facility complete | End 2026 |
| DFS (Definitive Feasibility Study) published | Q1 2027 |
| Commercial production | 2028 (target) |
| Full feedstock throughput | 40,000 mt/day by 2030 |
In May 2026, Round Top received a $14.2 million grant from the Texas Semiconductor Innovation Fund — the first major grant award for the project — to accelerate heavy rare earth development. USAR estimates the project will generate approximately 260 jobs and represent more than $1.4 billion in capital investment in West Texas.
Round Top in the US Rare Earth Supply Chain
Round Top’s HREE profile makes it strategically distinct from MP Materials’ Mountain Pass operation in California, which is a light rare earth producer focused on neodymium-praseodymium (NdPr). Round Top is specifically designed to supply dysprosium and terbium — the two HREEs critical for high-temperature NdFeB magnets used in EV motors, wind turbines, and defence applications. No domestic source of either element currently operates at commercial scale in the United States.
USAR’s integrated strategy connects Round Top’s HREE output directly to its Stillwater, Oklahoma magnet manufacturing facility, which commissioned Phase 1a of sintered NdFeB magnet production in March 2026. The Round Top-to-Stillwater supply chain represents the most advanced domestic mine-to-magnet pathway for heavy rare earths currently under development in the US. For a broader view of where Round Top sits in the global project pipeline, see the Top 10 Western rare earth supply chain projects.
For USAR’s latest financial results and project updates, see the USA Rare Earth Q1 2026 results.
Round Top Project — Key Facts
| Data Point | Detail |
|---|---|
| Location | Sierra Blanca, Hudspeth County, Texas — ~85 miles SE of El Paso |
| Operator | USA Rare Earth, Inc. (Nasdaq: USAR) |
| Land tenure | Texas state land lease — Texas General Land Office; ~950 acres + 9,345 acres prospecting rights |
| Deposit type | Rhyolite laccolith; yttrofluorite-hosted REE mineralisation |
| Resource mass (est.) | ~1.6 billion tonnes (Texas Bureau of Economic Geology) |
| REE profile | 16 of 17 REEs; ~70% heavy rare earths by content |
| Key HREEs | Dysprosium, terbium, yttrium, erbium, holmium, thulium, ytterbium |
| Co-products | Lithium, gallium, beryllium, hafnium, zirconium |
| Mining method | Open pit, heap leach |
| Throughput target | 40,000 mt/day by 2030 |
| Commercial production target | 2028 |
| EPCM partners | Fluor Corporation + WSP Global |
| Government support | $14.2m Texas Semiconductor Innovation Fund grant (May 2026) |
What is the Round Top rare earth project?
Round Top is a heavy rare earth and critical minerals deposit located at Round Top Mountain in Hudspeth County, west Texas, approximately 85 miles southeast of El Paso. It is operated by USA Rare Earth, Inc. (Nasdaq: USAR) under a long-term lease with the Texas General Land Office and is the most advanced HREE development project in the United States.
What rare earth elements does Round Top contain?
Round Top hosts 16 of the 17 rare earth elements. Approximately 70% of the total REE content is made up of heavy rare earths, including dysprosium, terbium, yttrium, erbium, holmium, thulium, and ytterbium — making it one of the few deposits outside China capable of supplying HREE critical for high-performance NdFeB permanent magnets. The deposit also contains lithium, gallium, beryllium, hafnium, and zirconium.
When will Round Top begin commercial production?
USA Rare Earth is targeting commercial production at Round Top in 2028 under its Accelerated Mining Plan. A Preliminary Feasibility Study is due Q3 2026 and a Definitive Feasibility Study is targeted for Q1 2027. By 2030, the operation aims to extract approximately 40,000 metric tonnes per day of rare earth and critical mineral feedstock.
Who owns Round Top and what is the TMRC acquisition?
USA Rare Earth, Inc. is the sole operator of Round Top. In March 2026, USAR announced a definitive agreement to acquire Texas Mineral Resources Corp. (OTCQB: TMRC), which held an 18.6% interest in the project, in an all-stock deal valued at approximately $73 million. The acquisition is expected to close by Q3 2026, making USAR the 100% economic beneficiary of Round Top.
How does Round Top differ from MP Materials’ Mountain Pass mine?
Mountain Pass in California is a light rare earth operation focused primarily on neodymium-praseodymium (NdPr). Round Top is specifically designed to produce heavy rare earths — dysprosium and terbium in particular — which are the elements most critically needed for high-temperature permanent magnets used in EV motors and defence systems. No US mine currently produces dysprosium or terbium at commercial scale, making Round Top’s development strategically significant.
