American Tungsten Begins First Utah Drill Program as US Seeks Domestic Supply
Key Takeaways
- Maiden drilling has commenced at Dutch Mountain on 28 August 2026, with 11 holes across 1,000 metres targeting the Fraction Lode contact skarn — the site of the last US tungsten mine to operate, which closed in 2017.
- Pads 6 to 10 represent the first-ever drilling on approximately 600 metres of untested eastern strike, with Pads 9 and 10 sitting directly on a peak soil anomaly of 504 ppm W.
- Surface rock chips returned grades up to 11,764 ppm W (1.48% WO₃) across 94 samples, underpinning the drill targets — though AT4 cautions this data is early-stage and not suitable for Mineral Resource estimation.
- Executive Order 14415, signed 20 July 2026, requires defence contractors to demonstrate active domestic tungsten sourcing efforts from January 2027, with China controlling over 80% of global supply and export controls already in effect since February 2025.
- AT4's US subsidiary was selected by the Department of Energy to negotiate a potential award of up to US$18 million under the ASCEND programme for domestic antimony smelting capacity, though no binding agreement has been reached.
Maiden drilling gets underway at Dutch Mountain as US tungsten supply urgency mounts
A drill rig has been mobilised and the maiden drill program has commenced at American Tungsten & Antimony Ltd‘s Dutch Mountain Tungsten Project in Tooele County, Utah. The timing is significant: the US has not produced domestic tungsten since 2017, when the Fraction Lode mine at Dutch Mountain last operated, and Executive Order 14415 (signed 20 July 2026) requires defence contractors to demonstrate active efforts to qualify domestic sources from January 2027.
AT4 (ASX: AT4, OTCQB: ATALF) sits on the site of the last US tungsten mine to operate, positioning the company at the centre of a tightening domestic supply debate.
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Phase 1 drill program targets high-grade skarn mineralisation across 11 holes
The Phase 1 program comprises approximately 1,000m of drilling across 10 drill pads and 11 holes, drilled by Energold Drilling Corp using man-portable diamond core equipment. Drilling commenced 28 August 2026.
Key program parameters:
- Hole depths planned between 60m and 100m
- Six holes at Pads 4 and 5 directly testing the Fraction Lode contact skarn beneath and along strike of historic workings
- Pads 6 to 10 step east along approximately 600m of untested strike on the same limestone-monzonite contact
- Assay laboratory: American Assay Laboratories (AAL), Sparks, Nevada, using sodium peroxide fusion with ICP-OES finish
Pads 6 to 10 represent ground that has never previously been tested by drilling. Historic mining in the district was confined to where the contact outcrops; these holes provide the first test of skarn development along its concealed continuation. Pads 1, 2 and 3 are approved and permitted but are reserved for a subsequent phase, pending geometry confirmation from Pads 4 and 5.
| Pad | Target | Holes | Planned Depth (m) | Target Rationale |
|---|---|---|---|---|
| Pad 4 | Fraction Lode workings | 3 | 60–100 | Direct test of the Fraction Lode contact skarn beneath the historic workings and along strike to the north |
| Pad 5 | Fraction Lode workings | 3 | 60–100 | Direct test of the Fraction Lode contact skarn beneath the historic workings and along strike to the east |
| Pad 6 | Fraction Lode eastern extension | 1 | 80 | Tests the along-strike continuation of the Fraction Lode trend; collared in granite/skarn to capture structural measurements and determine skarn orientation |
| Pad 7 | Fraction Lode eastern extension | 1 | 60 | Tests the along-strike continuation of the Fraction Lode trend |
| Pad 8 | Fraction Lode eastern extension | 1 | 80 | Tests the south-dipping contact beneath sedimentary cover, coincident with elevated soil result of 109 ppm W |
| Pad 9 | Fraction Lode eastern extension | 1 | 50 | Tests the south-dipping contact beneath sedimentary cover, coincident with peak soil result of 504 ppm W |
| Pad 10 | Fraction Lode eastern extension | 1 | 70 | Tests the south-dipping contact beneath sedimentary cover, coincident with peak soil result of 504 ppm W |
Surface sampling confirms high-grade tungsten anomalism over 700 metres
Drill targeting at Dutch Mountain is underpinned by a first-pass surface sampling program comprising 123 soil samples and 94 rock chip assay results.
Top rock chip results from the program:
- Sample 2029819: 11,764 ppm W (1.48% WO₃)
- Sample 2029525: 8,217 ppm W (1.04% WO₃)
- Sample 2029514: 7,772 ppm W (0.98% WO₃)
- Sample 2029595: 5,988 ppm W (0.76% WO₃)
- Sample 2029531: 5,223 ppm W (0.66% WO₃)
The peak soil result of 504 ppm W is situated between Pads 9 and 10, the same eastern extension that Pads 6 to 10 are designed to test. Tungsten anomalism at the Fraction Lode extends approximately 700m along the interpreted skarn contact, with a parallel trend of approximately 500m defined at the Stardust workings.
Coincident molybdenum (up to 606 ppm Mo) and tin (up to 493 ppm Sn) indicate a fertile, zoned magmatic-hydrothermal skarn system.
Important cautionary note: Rock chip samples are selective in nature, taken from surface exposures and historical workings, and are not necessarily representative of the grade, width, or continuity of mineralisation. Soil results are reported as pathfinder values in ppm W and are not grades. This data is early-stage and not suitable for Mineral Resource estimation.
CEO Casper Adson
“The first modern assay results from the Project returned high-grade tungsten from rock chips at surface. The results have been mapped to intrusive contacts rather than discrete historical workings which has allowed ten priority targets to be identified for followup drilling…”
What is a tungsten skarn, and why does deposit type matter to investors?
A contact-metasomatic (skarn) tungsten system forms where an igneous intrusion bakes surrounding limestone. The heat and fluids from that interaction produce scheelite (CaWO₄), the primary tungsten ore mineral. Dutch Mountain’s mineralisation is hosted in exactly this setting: a quartz-monzonite intrusion in contact with the Ochre Mountain Limestone.
Skarns are commercially significant because they can host high-grade zones and are amenable to conventional gravity concentration methods, which is the processing approach AT4 is pursuing. That matters because gravity concentration is a well-understood, lower-capital technique for recovering dense minerals like scheelite.
The end product AT4 is targeting is ammonium paratungstate (APT), the principal traded tungsten intermediate. APT is the feedstock from which tungsten oxides, metal powders, and carbide are produced. Tungsten carbide is used in drill bits, armour-piercing applications, and electronics. Understanding the chain from skarn ore to APT helps frame why both the geology and the processing strategy matter to the investment case.
From mine to metal: AT4’s vertical integration strategy takes shape
AT4’s proposed domestic supply chain runs in three steps: Dutch Mountain ore to the Dutch Mountain Processing Facility (a tungsten concentrator approximately 25km from the project) and then to a proposed APT circuit at the Del Sol Refinery in Nevada.
Civil works and site establishment have been completed at the 100%-owned Dutch Mountain Processing Facility. Works completed include site clearance and road grading, construction of a laydown pad, and identification and tagging of reusable process equipment, including the triple-deck Deister finishing table and the thickener. Restart readiness is now focused on engineering and metallurgical confirmation ahead of major equipment commitment. A Dutch Mountain sample has been collected for metallurgical characterisation at Del Sol, with results expected to inform the final configuration of the gravity concentration circuit.
The second drill program is also taking shape. Two CS14 diamond drill rigs have been contracted with Energold Drilling Corp and are expected to mobilise to the Tennessee Mountain Tungsten Project in Nevada in October 2026, subject to receiving approvals. The planned program comprises approximately 2,000m across 15 proposed drill pads, testing the W-Mo skarn system. Permitting is by way of a Plan of Operations lodged with the US Forest Service, Humboldt-Toiyabe National Forest. Beneficiation test work is ongoing at Del Sol on both Dutch Mountain and Tennessee Mountain samples, with no results reported in this announcement.
Chairman Tim Morrison
“…The commencement of drilling at Dutch Mountain is a step towards building out a fully integrated domestic United States tungsten supply chain running from mined ore, through the Dutch Mountain concentrator, to the proposed APT circuit at Del Sol…”
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Policy and land position reinforce the investment case
The policy backdrop framing AT4’s activity is unusually explicit. Key developments in sequence:
- The US has not produced domestic tungsten since 2017
- China controls over 80% of global tungsten output; export controls on APT, tungsten oxide, and tungsten carbide took effect from February 2025 and were consolidated in January 2026
- 10 U.S.C. 4872 (as amended by the FY2026 National Defense Authorization Act) prohibits DoD procurement of covered materials from China, Russia, Iran, or North Korea
- Executive Order 14415 (20 July 2026): from 1 January 2027, non-availability waivers require a formal mitigation plan showing active efforts to source from non-adversary supply chains
- Project Vault: an initiative of approximately US$12 billion to develop a critical minerals stockpile (a US Export-Import Bank loan of up to US$10 billion together with around US$2 billion from private industry), which may include tungsten and antimony
AT4 has also expanded its land position, staking 15 new unpatented lode mining claims covering approximately 310 acres to the south and west of its existing Dutch Mountain claim block, extending coverage along the interpreted limestone-monzonite contact.
On 19 August 2026, AT4 announced that its US subsidiary Trigg Minerals USA was selected by the US Department of Energy to commence negotiations on the scope and terms of a potential award of up to US$18 million under the ASCEND programme, relating to domestic antimony smelting capacity. Selection to negotiate is not an award. No binding agreement has been entered into and there is no certainty that negotiations will result in funding, or as to the amount, terms, or timing of any funding.
Looking ahead, AT4’s stated next steps are:
- Complete the maiden Dutch Mountain drill program and report assay results as received
- Commence Tennessee Mountain drilling, expected October 2026 (subject to approvals)
- Continue Del Sol beneficiation test work on Dutch Mountain material
- Undertake infill and extensional soil sampling over the newly staked claims
- Complete detailed geological mapping of the interpreted skarn-to-intrusive contact
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