Grande Portage Reports Advancements of Transportation Infrastructure at the New Amalga Gold Project

VANCOUVER, December 16, 2025 - Grande Portage Resources Ltd. (TSXV:GPG)(OTCQB:GPTRF)(FSE:GPB) ("Grande Portage" or the "Company") is pleased to announce an update regarding transportation infrastructure for its New Amalga Gold property in Southeast Alaska. The current development concept for the project envisions a small-footprint underground mining operation with third-party offsite processing, eliminating the need for an onsite mill or tailings storage facility.

Update on Project Access Road:

In August 2025 the Company announced its application for a State of Alaska road easement which would encompass approximately the initial one-third of the total road development required to establish access to the project site. The remaining two-thirds of the route is located on Federal land requiring a separate regulatory process.

The State easement application has now progressed to the adjudication stage at the Department of Natural Resources, a significant milestone which will, in due course, lead to a public notice period. The company has also signed a contract for an archeological and cultural resources survey to take place in early spring - the primary baseline study which will be required before road construction can begin.

The easement for this initial road segment will enable the start of mine access road construction on State Land while advancing the Federal regulatory process for the portions of the project under Federal land tenure. Importantly, it will also provide the near-term benefit of establishing a helicopter staging area much closer to the project site compared to the staging area used in previous field seasons, which was located at the Juneau International Airport. This will greatly reduce the helicopter cycle distance for shuttling drilling equipment and supplies, improving efficiency and also reducing noise impacts to residential areas of Juneau.

Update on Ore Barge Dock at Cascade Point:

The Company is also pleased to provide an update on developments related to the proposed ore barge dock at Cascade Point, following the Company's June 2024 announcement of a Letter of Intent ("LOI") with Goldbelt, Inc. ("Goldbelt"), Juneau's Alaska Native Corporation.

Cascade Point is located approximately 15 miles (24 km) from the New Amalga Mine project and is accessible via Glacier Highway, an existing state-maintained roadway. The design for the ore dock will be integrated with Goldbelt's planning for a future Alaska Marine Highway System ferry terminal at the site, intended to improve marine access and transportation infrastructure in the Juneau area. The location can accommodate both functions in separate areas, with flexibility for the two projects to be built either concurrently or sequentially.

Since the execution of the LOI, significant progress has been made on the broader Cascade Point ferry terminal project, which is being advanced by the Alaska Department of Transportation & Public Facilities ("ADOT&PF") in coordination with Goldbelt. In July 2025, ADOT&PF awarded a US$28.5M contract for Phase 1 work at Cascade Point, covering uplands development, site preparation, and engineering and environmental studies. This work represents a key step towards preparing the site for construction of marine infrastructure.

Subsequently, in December 2025 the State of Alaska signed a US$1.3M contract with Juneau Hydro to extend hydropower infrastructure to Cascade Point. The planned electrification will provide grid-based renewable power to the site, supporting lower operating costs and reduced emissions relative to diesel-based alternatives.

Grande Portage further reports that Goldbelt has provided the Company with the next phase of engineering drawings for the proposed ore barge dock to be co-located at Cascade Point. The dock concept is intended to utilize available space at Cascade Point to operate alongside the passenger ferry terminal in a separate area of the site, subject to permitting, engineering refinement, and final agreements.

The dock is designed for barge loading of containerized ore using forklifts, rather than bulk (loose) ore via conveyor belt. This minimizes the construction of large infrastructure at the site while reducing any risk of spillage or dust generation, drawing on lessons learned from other regional ore terminals, including the requirements adopted by the City of Skagway requiring that future ore shipments through the Port of Skagway be containerized rather than handled in bulk.

"The advancement of the Cascade Point ferry terminal, combined with planned hydropower access and receipt of preliminary dock facility designs, represents significant progress since our initial announcement with Goldbelt," said Ian Klassen, President and CEO of Grande Portage Resources. "These developments support our long-held objectives of establishing a practical, efficient, and environmentally responsible marine logistics solution for the New Amalga project."

Project Summary:

The New Amalga Gold Project remains open to expansion in multiple directions and hosts 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). The current development concept envisions a small-footprint underground mining operation which would transport material offsite for processing by a third party, eliminating the need for an onsite gold recovery plant or tailings storage facility.

This setup is designed to provide several benefits:

• Eliminates the need to build a gold recovery plant, minimizing mine footprint, power requirements and reducing project construction CAPEX.

• Eliminates the need to develop a tailings disposal facility at the site, as no tailings would be generated.

• Removes the need for permanent waste rock storage facilities. Waste rock generated from mine development would be returned to the underground workings as stope backfill.

• No use of chemical reagents for gold processing at the site.

• Dramatically reduces land usage and overall environmental footprint.

• Greatly facilitates post-mining closure and reclamation.

• Simplifies the environmental review and permitting process.

Project Highlights:

• A 100% interest in the New Amalga Gold Project, located near infrastructure only 25km north of Juneau, Alaska and 6km from paved all-season highway (Fig. 2)

• The property is host to at least 8 large, long, gold bearing mesothermal veins

• 240 drill holes from 55 platforms totaling ~65,000 m confirm a large gold-quartz system

• Past drilling produced multi-ounce assays on several veins. Select samples include:

Deep Trench Vein: 15.3m grading 37.1 g/t Au, 8.3m grading 58.6 g/t Au, 11.6m grading 28.3 g/t Au
Goat Vein: 2.1m grading 74.2 g/t Au, 6.3m grading 15.7 g/t Au
Main Vein: 3.1m grading 79.2 g/t Au, 2.1m grading 37.2 g/t Au, 3.1m grading 13.9 g/t Au
Ridge Vein: 1.5m grading 43.0 g/t Au, 1.5m grading 29.2 g/t Au
Sleeping Giant Vein: 2.1m grading 15.4 g/t Au, 3.2m grading 20.7 g/t Au

See Fig. 1 below for approximate locations of selected intercepts.

• The Company's updated NI43-101 Mineral Resource Estimate (MRE) with an effective date of July 17, 2024 reported 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 deposit is open to the north, south and at depth.

• Goat vein surface outcrop channel samples assayed 129.02 g/t gold (3.76 opt) and 290 g/t gold (8.46 opt) with 224 g/t silver (6.53 opt)

• LiDAR survey of property discovered numerous targets - the first of these tested confirmed gold discovery

• Received excellent metallurgical recoveries up to 98.2%

• Completed 6+ years of environmental baseline water sampling

• Current development strategy envisions a small-footprint underground mining operation with third-party offsite processing, eliminating the need for an onsite mill or tailings storage facility. This configuration reduces capital costs, greatly minimizes the project's environmental footprint, and facilitates permitting.

• LOI signed with Goldbelt Inc (an Alaska Native Corporationorganized under the Alaska Native Claims Settlement Act) for development of an ore export terminal at Cascade Point, Goldbelt's privately held parcel located only 22km from the project site.

• NI43-101 Preliminary Economic Assessment in progress, expected completion 2026 Q1.

Fig. 1: Approximate Locations of Selected Intercepts

Fig. 2: 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% interest 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.

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: Ian@grandeportage.com

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 forward-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 place 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

SOURCE: Grande Portage Resources Limited