Mr. Ian Klassen reports

GRANDE PORTAGE RESOURCES ANNOUNCES COMPLETION OF 2026 DRILL PROGRAM AND SUMMER FIELD SEASON

Grande Portage Resources Ltd. has completed the 2026 summer fieldwork and drilling program at the New Amalga gold project located in southeast Alaska. The drill rig and drill crews have now been demobilized after a safe and successful season.

Work completed during summer 2026 included:

• Completion of 12 drill holes totalling 3,255 metres from five platforms -- these holes targeted key areas of the deposit to gather critical resource definition, geotechnical and hydrogeological data;
• Development of five groundwater monitoring wells and installation of one vibrating-wire piezometer (VWP) -- enables retrieval of deep groundwater samples to establish baseline water quality and inform design of a future mine water treatment plant, as well as informs hydrogeological model to determine expected groundwater inflows into future underground workings;
• Detailed geotechnical logging and testing -- including hundreds of point-load test (PLT) samples to refine stoping parameters and crown pillar criteria;
• Extensive biological and botanical surveys -- covering both the mine site and the Cascade Point ore barge dock area, these studies included wetlands mapping, invasive and sensitive plants surveys, avian surveys, terrestrial wildlife surveys, aquatic biomonitoring, water, and soils sampling. This provides criteria for facility design and will inform the upcoming NEPA environmental review process;
• Geohazard and floodplain surveys -- to identify areas at risk for landslides, avalanches and flooding in order to inform design of mine facilities;
• Cultural resource surveys -- including archeological field investigations of the mine facilities areas, access road alignments, and the Cascade Point ore barge dock site;
• Road traffic surveys -- to gather data on traffic patterns along the public highway between the mine site and the Cascade Point ore barge dock site;
• Construction of meteorological towers and stream gauging infrastructure -- to gather data on weather and river conditions. This marks the first long-term infrastructure built for the project, intended to be utilized for the life of the future mining operation. Final sensor calibration is ongoing and the company intends to provide more information in an upcoming news release.

These items provide key baseline data and engineering criteria which are currently being incorporated into the engineering designs for the project's plan of operations, which is scheduled to be submitted to the United States Forest Service in March, 2027.

Submission of a completed plan of operations will initiate the federal NEPA environmental review process. This will be facilitated by the project's status as a FAST-41 Covered project which provides federal co-ordination and oversight of the various regulatory agencies involved in the review process.

The company intends to continue supplemental field activities during the autumn months, including fall-season wildlife surveys and additional cultural resources surveys of the project area.

Ian Klassen, the company's president and chief executive officer, said: "We are very pleased to have completed a safe and highly productive 2026 field season. The extensive geological, geotechnical, hydrogeological, environmental and cultural data collected this summer are all critical inputs to complete our comprehensive plan of operations for submission in March, 2027. With our baseline studies progressing, our federal permitting schedule established under FAST-41 and a direct-shipping development strategy supported by our definitive ore offtake agreement with Ocean Partners, we are steadily advancing the key technical and regulatory work needed to move this high-grade gold project toward development."

Kyle Mehalek, PE, is the QP within the meaning of National Instrument 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 Ltd.

Grande Portage Resources 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 kilometres north of Juneau, Alaska. The company holds a 100-per-cent 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 160 km 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, PhD, PGeol, PEng (DRW Geological Consultants Ltd.), with an effective date of July 17, 2024. Additional information on the New Amalga mine project is available in the technical report titled "Preliminary Economic Assessment for the New Amalga Gold Project Juneau District, Southeast Alaska" dated Feb. 11, 2026, which is available under Grande Portage's SEDAR+ profile.

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