REG - Guardian Metal Rsrc. - Pilot Mountain Pre-Feasibility Progress Update

Guardian Metal ResourcesAnnouncement

19/12/2025 07:00

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RNS Number : 2043M  Guardian Metal Resources PLC  19 December 2025

19 December 2025

Guardian Metal Resources plc

('Guardian Metal' or the 'Company')

Pilot Mountain Pre-Feasibility Progress Update

Maiden S-K 1300 Technical Summary Report Delivers 16% Increase in Open Pit
Constrained Indicated Mineral Resources vs 2018 Scoping Study; Drilling
Ongoing

Guardian Metal Resources plc (LON:GMET/OTCQB:GMTLF), a strategic exploration
company focused on tungsten in Nevada, USA, is pleased to announce the
submission to the SEC of a S-K 1300 Technical Summary Report ("TRS") and
updated Mineral Resource Estimate ("Resource" or "MRE") on the 100%-owned
Pilot Mountain tungsten Project ("Pilot Mountain" or the "Project") located in
Nevada, USA. Importantly, in accordance with Regulation S-K 1300 17 CFR Part
229 Subpart 229.1300 ("S-K 1300"), the updated MRE is pit-constrained and
therefore potentially suitable for open-pit mining, offering a potential
pathway to development and positioning the Company, subject to permitting,
financing and further technical work, to support the development of a
domestically mined source of tungsten in the United States for the first time
in more than a decade. The TRS will also underpin the technical disclosures
required for the Company's planned listing on a U.S. securities exchange.

Tungsten is a key defence and industrial metal and has been designated as a
strategic priority by the U.S. government. Guardian Metal's mission is to
bring into production two of its tungsten projects, Pilot Mountain and
Tempiute, as the cornerstone of U.S. tungsten supply, directly supporting
national efforts to reshore mined production. Significantly, this would mark a
major step in the U.S. effort to reduce reliance on foreign supply chains and
reinforce economic and defence security, laying the groundwork for durable,
long-term value creation.

The TRS, dated 15 December 2025, was prepared by the Qualified Person RESPEC
Company LLC ("RESPEC ") of Rapid City, South Dakota, USA in accordance with
the United States Securities and Exchange Commission ("SEC") requirements
under S-K 1300 and will be publicly available via the SEC Electronic Data
Gathering, Analysis and Retrieval (EDGAR) system in due course.

 

Oliver Friesen, CEO of Guardian Metal, commented:

"Supported by the U.S. Department of War's US$6.2 million Defense Production
Act (DPA) Title III investment in Guardian Metal's wholly-owned subsidiary,
Golden Metal Resources (USA) LLC, we are making strong progress toward
completing the Pre-Feasibility Study ("PFS") and advancing towards our goal of
delivering the first new mined source of tungsten on U.S. soil in more than a
decade.

"The inaugural pit-constrained Mineral Resource for Desert Scheelite, prepared
in accordance with S-K 1300, represents the culmination of over 12 months of
diligent drilling completed by our in-country Nevada-based operations team.
This Resource, which includes a 16% increase in pit constrained Indicated
tonnage, establishes a solid foundation for future resource growth, and, more
importantly, represents an important step in supporting a potential U.S.
listing.(1)

"Concurrently, drilling is ongoing at Desert Scheelite, targeting multiple
areas that remain open for expansion. A second drill rig has been secured and
is scheduled to mobilise early in the New Year, enabling an expanded drill
programme at Desert Scheelite as well as several other underexplored tungsten
zones across the Project including the Garnet Zone. Results from this work are
expected to be incorporated into a future MRE update, which will underpin the
progressing PFS.

"Now more than ever, the Company believes that the United States requires a
secure domestically mined source of tungsten, and Guardian Metal is firmly
focused on delivering that outcome."

 

Marc Leduc, P.Eng., Operations Manager of Guardian Metal, commented:

"Preparation of the Pre-Feasibility Study continues to advance well. All key
technical and engineering studies required to support the PFS are currently
underway, including mine planning, metallurgy, infrastructure studies,
hydrogeological drilling, and environmental baseline studies to support mine
permitting.

"The outcomes of these workstreams will be integrated into a comprehensive
development plan, which will form the basis of the Project's Mine Plan of
Operations and underpin the permitting pathway and subsequent mine development
activities."

 

MAIDEN S-K 1300 MINERAL RESOURCE AND PFS PROGRESS

·    The Company has successfully completed its first MRE prepared in
accordance with S-K 1300 at Desert Scheelite, representing only one of the
Project's four known at-surface tungsten-rich skarn zones. The PFS is
advancing well with a highly qualified multi-disciplined specialist team.

 

·    The establishment of the Project's first ever Resource, prepared in
accordance with S-K 1300, represents a key milestone as the Company builds
towards a potential listing on a U.S. securities exchange.(1)

 

·    The Resource was completed by RESPEC Company LLC - an experienced
specialist mining engineering firm based in Rapid City, South Dakota and Reno,
Nevada (Table 1).

 

·     Importantly, the Resource incorporates data from 68 drillholes at
Desert Scheelite completed by the Company. Since the MRE data cutoff of
October 20, 2025, a further eight drillholes have been completed, with
additional drilling planned to further test extensions of Desert Scheelite
where the Resource remains open along strike (east and west) and down dip.
These recently completed and future planned drillholes will be incorporated
into a further updated MRE expected prior to completion of the PFS.

 

·    The MRE update will include a recent intercept in drillhole PM25-065
which returned a 26.8m  intersection (from 172.17m - 198.97m) with one of the
strongest visual (under ultra-violet light) intersections of scheelite
(CaWO(4)) mineralisation noted by the Company on the Project to date.

 

·    To support the planned 2026 MRE, the Company has secured a second
exploration drill rig, scheduled to arrive on site early in 2026. This
additional rig will enable the testing of several known at-surface tungsten
zones across the Project that have not yet been adequately drill
tested-including at Desert Scheelite and the Garnet Zone-and will also provide
additional capacity for further engineering-related drilling.

 

·    The PFS, supported by a US $6.2m DoW DPA III investment in Guardian
Metal's wholly-owned subsidiary, Golden Metal Resources (USA) LLC(2), is
progressing well and is being led by the Company's Operations Manager, Marc
Leduc, P.Eng., a highly experienced mine builder. Mr. Leduc and the Company's
technical team are joined by a group of highly experienced partners who are
engaged to progress the various ongoing PFS workstreams including:

o Samuel Engineering, Inc. (Denver, Colorado)*: Overall PFS lead, metallurgy,
process engineering and plant design, financial modelling and final report
preparation.

o RESPEC Company LLC (Rapid City, South Dakota and Reno, Nevada): Resource
modelling, geotechnical  engineering and mine design.

o KTW Environnemental (Boise, Idaho): Project permitting.

o Life Cycle Geo LLC (Longmont, Colorado): Geochemical characterisation and
baseline data collection.

o Clear Creek Associates (Scottsdale, Arizona): Hydrogeology.

o Qualus, LLC (Lake Mary, Florida): Power engineering.

o Westland Engineering & Environmental Services, a Trinity Consultants
Team (Reno, Nevada): Baseline data collection and permitting.

o NewFields Mining Design & Technical Services, LLC (Denver, Colorado):
Tailings and waste design.

o Reliant Well Drilling and Pump Corp. (Tucson, Arizona): Hydrogeological
drilling services.

 

·    In total, more than 25 specialists from 8 independent firms with
decades of U.S.-focused mine design, engineering, procurement and construction
management experience are currently engaged by the Company's Pilot Mountain
PFS team. Guardian Metal's owners team includes a group of geologists,
geotechnicians and engineers with over 100 years' of combined exploration,
mine building and operations experience.

 

·    The PFS study is expected to be completed by the end of H1 2026, and
mine permit applications will be submitted promptly thereafter. Further PFS
progress updates will be provided and any preliminary results from any of the
above ongoing workstreams will be released when allowable, including pending
drilling results from both the Desert Scheelite and Garnet Zones. The
Company's objective is to achieve initial commercial production before the end
of 2028.

 

MINERAL RESOURCE DETAILS

The updated Mineral Resource Estimate applies a 0.06% tungsten trioxide
(WO₃) cut-off grade, reflecting increased tungsten prices since the 2018 MRE
and the planned open-pit mining approach. The MRE also incorporates the
favourable tungsten recoveries demonstrated in historical metallurgical test
work. An initial preliminary pit design has been developed and supports both
the Indicated and Inferred Mineral Resources.

Importantly, the Desert Scheelite Deposit now comprises a high proportion of
pit-constrained Indicated Mineral Resources, providing a strong foundation for
the ongoing PFS. The now established MRE, prepared in accordance with S-K
1300, is expected to grow further as results from ongoing exploration drilling
are incorporated into a future update.

Drilling completed by the Company during 2024 and 2025 successfully achieved
its key objectives, including re-estimating the Mineral Resource under S-K
1300 based on additional drilling and updated technical work, upgrading
overall resource confidence, generating material for detailed metallurgical
test work (currently underway), and providing the data required to support
mine planning and permitting activities, which are also now in progress.

When compared to the Mineral Resource estimate underpinning the 2018 Scoping
Study, the updated resource sensitivity analysis shows that the tonnage of
Indicated Resources within a projected open-pit design has increased by
approximately 16%.

 

Table Error! No text of specified style in document.  Desert Scheelite
Mineral Resources

                                   Cut-off Grade                  Average Grade                    Contained Metal

 Mineral Resource Classification                  Tonnes
                                   % WO(3)        WO(3) (%)              Ag (g/t)  Cu (%)  Zn (%)  WO(3) (t)         Ag                    Cu          Zn

                                                                                                                     (oz)                  (t)         (t)
 Indicated                         0.06              8,694,000    0.206  12.43     0.085   0.315      17,900            3,475,000             7,400       27,400
 Inferred                          0.06              1,784,000    0.169  12.00     0.063   0.225         3,000              689,000           1,100          4,000

 

Notes:

1    The effective date of Desert Scheelite Mineral Resource statement is
December 1, 2025.

2     Mineral Resource stated in metric tonnes.

3    Average grades of the tabulations are comprised of the weighted average
of block-diluted grades within an optimised pit.

4    The Desert Scheelite Mineral Resource cut‑off grade of 0.06% WO₃
was selected by the authors. Operating assumptions were applied to establish a
theoretical pit limit, including a WO₃ price of $65,500/t, an average
recovery of 80% WO₃, a processing rate of 4,000 tonnes/day, $2.75/t mining
cost for open pit, $15.64/t processing cost, $3.00/t processed for G&A,
and an 83% payability. Blocks outside the pit limit are not considered to be
economic at this time.

5    The accessory metals Ag, Cu, and Zn shown in this table are the
quantities contained within the mineral resources using the cut-off grade
established for the primary commodity (WO(3)). No independent cut-off grade
has been applied to these accessory metals. Reported quantities of accessory
metals are therefore considered by-products of the primary metal resource and
their value is contingent upon the ability to economically extract the
by-products along with the primary commodity.

6    The estimate of mineral resources may be materially affected by
geology, environmental, permitting, legal, title, taxation, sociopolitical,
marketing, or other relevant issues.

7    Rounding as required by reporting guidelines may result in apparent
discrepancies between tonnes, grade, and contained metal content.

8    Mineral Resources are not Mineral Reserves and do not have demonstrated
economic viability. An Inferred Mineral Resource has a lower level of
confidence than an Indicated Mineral Resource and must not be converted to a
Mineral Reserve. RESPEC reasonably expects that continued exploration and
delineation will upgrade the majority of Inferred Mineral Resources to
Indicated Mineral Resources.

 

FURTHER PFS UPDATES

Ongoing work includes open-pit mine design and optimisation, detailed
metallurgical test work, hydrogeological drilling to support future mine
permitting, geochemical characterisation of waste rock, tailings design, and
geotechnical investigations to support the planned open pit and associated
mine infrastructure. Studies assessing options for all required mine and mill
infrastructure are also underway.

The PFS is being coordinated by Guardian Metal's in-house team in
collaboration with Samuel Engineering, Inc. and the various engineering
contractors outlined above. Resource drilling at Desert Scheelite is ongoing
and will ramp up into Q1 2026 upon the delivery of an additional drilling rig,
with drillholes also planned at some of the other Project target areas. An
updated MRE is expected prior to the completion of the PFS which is targeted
for completion by end of H1 2026.

References

1(                    ) Company announcement, Intention to
list in the US, dated 8 September 2025

(
https://polaris.brighterir.com/public/guardian_metal_resources/news/rns/story/rdo0dpx
(https://polaris.brighterir.com/public/guardian_metal_resources/news/rns/story/rdo0dpx)
)

2              Company announcement, U.S. Department of Defense
Awards $6.2M to Golden Metal Resources for the Pilot Mountain Project, dated
23 July 2025

(
https://polaris.brighterir.com/public/guardian_metal_resources/news/rns/story/wvm0n3w
(https://polaris.brighterir.com/public/guardian_metal_resources/news/rns/story/wvm0n3w)
)

 

QUALIFIED PERSON

RESPEC is the author of the TRS and the Qualified Person under item 1302 of
Regulation S-K, has reviewed and approved the inclusions of its summary of the
TRS in this announcement.

This announcement includes a summary of the main elements of the PFS which is
included in a Technical Report Summary which has been prepared in accordance
with S-K 1300, as adopted by the SEC. The effective date of the MRE in the TRS
is 1 December 2025.

 

COMPETENT PERSON STATEMENT

The technical information contained in this disclosure has been read and
approved by Mr Nick O'Reilly (MSc, DIC, MIMMM QMR, MAusIMM, FGS), who is a
qualified geologist and acts as the Competent Person under the AIM Rules -
Note for Mining and Oil & Gas Companies. Mr O'Reilly is a Principal
consultant working for Mining Analyst Consulting Ltd which has been retained
by Guardian Metal Resources plc to provide technical support.

This announcement contains inside information for the purposes of Article 7 of
EU Regulation 596/2014 (which forms part of domestic UK law pursuant to the
European Union (Withdrawal) Act 2018).

 

Forward Looking Statements

This announcement contains forward-looking statements relating to expected or
anticipated future events and anticipated results that are forward-looking in
nature and, as a result, are subject to certain risks and uncertainties, such
as general economic, market and business conditions, competition for qualified
staff, the regulatory process and actions, technical issues, new legislation,
uncertainties resulting from potential delays or changes in plans,
uncertainties resulting from working in a new political jurisdiction,
uncertainties regarding the results of exploration, uncertainties regarding
the timing and granting of prospecting rights, uncertainties regarding the
timing and granting of regulatory and other third party consents and
approvals, uncertainties regarding the Company's or any third party's ability
to execute and implement future plans, and the occurrence of unexpected
events.

Actual results achieved may vary from the information provided herein as a
result of numerous known and unknown risks and uncertainties and other
factors.

Nothing in this announcement is intended to constitute an offer of securities
for sale or a solicitation of any offer to acquire securities in any
jurisdiction.

For further information visit www.Guardianmetalresources.com
(http://www.goldenmetalresources.com) or contact the following:

 Guardian Metal Resources plc                 Tel: +44 (0) 20 7583 8304

 Oliver Friesen (CEO)
 Cairn Financial Advisers LLP                 Tel: +44 (0) 20 7213 0880

 Nominated Adviser

 Sandy Jamieson/Jo Turner/Louise O'Driscoll
 Berenberg                                    Tel: +44 (0) 20 3207 7800

 Joint Broker and Financial Adviser

 Jennifer Lee/Ivan Briechle
 Tamesis Partners LLP                         Tel: +44 (0) 20 3882 2868

 Joint Broker

 Charlie Bendon/Richard Greenfield

About Guardian Metal Resources

Guardian Metal Resources PLC (LON: GMET, OTCQX: GMTLF) is a strategic mineral
exploration company driving the revival of U.S. mined tungsten production and
strengthening America's defense metal independence. The Company is advancing
two co-flagship tungsten projects, Pilot Mountain, one of the largest
undeveloped tungsten deposits in the U.S. and Tempiute, formerly America's
largest producing tungsten operation, both located in Nevada, one of the
top-rated mining jurisdictions in the U.S.

In July 2025, the U.S. Department of War (DoW) under Title III of
the Defense Production Act of 1950, as amended, invested US$6.2M in Golden
Metal Resources (USA) LLC, a wholly-owned subsidiary of Guardian Metal
Resources PLC, to support the Pilot Mountain PFS. The Company has announced
plans to pursue a U.S. listing in the first half of 2026.

Tungsten is a strategic metal critical to the defense, energy transition,
technology, and industrial sectors. In the context of shifting geopolitical
dynamics and tightening Chinese export restrictions, Guardian is well
positioned to play a leading role in re-establishing a secure, domestically
mined U.S. supply chain for this vital defense metal.

 

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