Grande Portage Initiates Preliminary Economic Assessment and Receives Gold Payability Terms of Up to 87%
1050 - 1090 West Georgia Street
Vancouver, British Columbia. V6E 3V7
Grande Portage Initiates Preliminary Economic Assessment and Receives Gold
Payability Terms of Up to 87%
Vancouver, British Columbia — October 20, 2025 – Grande Portage Resources Ltd. (TSXV: GPG) (OTCQB: GPTRF)
(FSE: GPB) (“Grande Portage” or the “Company”) is pleased to report two major advancements at its New Amalga Gold
Project in Southeast Alaska.
The project hosts a high-grade mineral resource of 1.4 million ounces of gold (indicated) and 0.5 million ounces (inferred) and
remains open to expansion in multiple directions. The current development concept envisions a small -footprint underground
mining operation with third-party offsite processing, eliminating the need for an onsite mill or tailings storage facility.
Strong Indicative Offtake Terms Confirm Marketability
Grande Portage has received indicative ore offtake terms from a leading global concentrate trading firm, showing gold payability
of 72% to 87%, depending on the grade of the shipment. Based on the Company’s conceptual production plan incorporating
sensor-based ore sorting, typical payabilities are expected to range from 80% to 85%.
The offtake study confirms that New Amalga ore is readily marketable to Asian base metal smelters, custom concentrates
facilities, roasting operations, and leach plants. Applicable treatment and refining charges (TC/RCs) are quoted at the copper
benchmark treatment charge plus $95 per tonne, and a $10 per contained gold ounce refining charge.
Preliminary Economic Assessment Initiated
Following this positive market feedback, Grande Portage has initiated an NI 43-101 Preliminary Economic Assessment (PEA).
The Company has contracted all required Qualified Persons (QPs) and technical specialists, many of whom have direct project
experience in Alaska, including at Pogo, Kensington, and Greens Creek, as well as within the Alaska DNR Office of Project
Management and Permitting.
An initial draft PEA is anticipated in early to mid-January, with final completion targeted for mid-to-late February 2026.
PEA Consultant Team:
• Core Geoscience LLC – Environmental, Permitting, Social & Community Impacts
• DRW Geological Consultants Ltd. – Geological Setting & Mineralization, Resource Estimates
• Mine Development Associates (RESPEC Inc.) – Capital & Operating Costs
• OreLogic LLC – Mining Methods, Recovery, Infrastructure, Market Studies, Economic Analysis
• SRK Consulting Inc. – Geotechnical & Hydrogeological Studies
1050 - 1090 West Georgia Street
Vancouver, British Columbia. V6E 3V7
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Ian Klassen, Grande Portage President and CEO comments: “The excellent gold payabilities in this indicative term sheet attest
to the marketability of the New Amalga ore as a highly desirable feedstock for third-party processing facilities. This validates our
strategy for developing the deposit as a DSO direct-ship operation, which will greatly reduce capital costs by avoiding the need
to construct a processing plant at the site, while de-risking the regulatory approval process by eliminating the requirement for a
tailings storage facility. We look forward to defining further technical and economic details as part of our upcoming PEA.”
Fig. 1: Location of the New Amalga Gold Project
Kyle Mehalek, P.E.., is the QP within the meaning of NI 43-101 and has reviewed and approved the technical disclosure
in this release. Mr. Mehalek is independent of Grande Portage within the meaning of NI 43-101.
About Grande Portage:
Grande Portage Resources Ltd. is a publicly traded mineral exploration company focused on advancing the New Amalga
Mine project, the outgrowth of the Herbert Gold discovery situated approximately 25 km north of Juneau, Alaska. The
Company holds a 100% inte rest in the New Amalga property. The New Amalga gold system is open to length and
depth and is host to at least six main composite vein-fault structures that contain ribbon structure quartz-sulfide veins.
The project lies prominently within the 160km long Juneau Gold Belt, which has produced over eight million ounces
of gold.
1050 - 1090 West Georgia Street
Vancouver, British Columbia. V6E 3V7
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The Company's updated NI#43-101 Mineral Resource Estimate (MRE) reported at a base case mineral resources cut -
off grade of 2.5 grams per tonne gold (g/t Au) and consists of: an Indicated Resource of 1,438,500 ounces of gold at
an average grade of 9.47 g/t Au (4,726,000 tonnes); and an Inferred Resource of 515,700 ounces of gold at an average
grade of 8.85 g/t Au (1,813,000 tonnes), as well as an Indicated Resource of 891,600 ounces of silver at an average grade
of 5.86 g/t Ag (4,726,000 tonnes); and an Inferred Resource of 390,600 ounces of silver at an average grade of 7.33 g/t
silver (1,813,000 tonnes). The MRE was prepared by Dr. David R. Webb, Ph.D., P.Geol., P.Eng. (DRW Geological
Consultants Ltd.) with an effective date of July 17, 2024.
ON BEHALF OF THE BOARD
"Ian Klassen"
Ian M. Klassen
President & Chief Executive Officer
Tel: (604) 899-0106
Email: [email protected]
Cautionary Statement Regarding Forward-Looking Information
This news release includes certain "forward -looking statements" under applicable Canadian securities legislation.
Forward-looking statements include estimates and statements that describe the Company's future plans, objectives or
goals, including words to the effect that the Company or management expects a stated condition or result to occur.
Forward-looking statements may be identified by such terms as "believes", "anticipates", "expects", "estimates", "may",
"could", "would", "will", or "plan". Since forw ard-looking statements are based on assumptions and address future
events and conditions, by their very nature they involve inherent risks and uncertainties as described in the Company's
filings with Canadian securities regulators. There can be no assurance that such statements will prove to be accurate, as
actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers
should not place undue reliance on forward-looking statements. The Company disclaims any intention or obligation to
update or revise any forward-looking information, whether as a result of new information, future events or otherwise,
other than as required by law.
Please note that under National Instrument 43 -101, the Company is required to disclose that it has not based any
production decision on NI 43-101-compliant reserve estimates, preliminary economic assessments, or feasibility studies,
and historically production decisions made without such reports have increased uncertainty and higher technical and
economic risks of failure. These risks include, among others, areas that are analyzed in more detail in a feasibility study
or preliminary economic assessment, such as the application of economic analysis to mineral resources, more detailed
metallurgical and other specialized studies in areas such as mining and recovery methods, market analysis, and
environmental, social, and community impacts. Any decision to pla ce the New Amalga Mine into operation at levels
intended by management, expand a mine, make other production -related decisions, or otherwise carry out mining and
processing operations would be largely based on internal non-public Company data, and on reports based on exploration
and mining work by the Company and by geologists and engineers engaged by the Company.
NEITHER THE TSX VENTURE EXCHANGE NOR ITS REGULATION SERVICE PROVIDER (AS THAT TERM IS
DEFINED UNDER THE POLICIES OF THE EXCHANGE) ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR
ACCURACY OF THIS NEWS RELEASE