Mr. Kelly Malcolm reports

BOREALIS MINING ADVANCES SANDMAN GOLD PROJECT TOWARD DEVELOPMENT WITH INITIATION OF DETAILED ENGINEERING, PERMITTING AND TECHNICAL WORK PROGRAMS

Borealis Mining Company Ltd. has installed detailed engineering, permitting and technical work programs at its Sandman gold project in Humboldt county, Nevada, as the company advances the project toward a future construction decision.

Following the results of its recently completed preliminary economic assessment (announced Feb. 19, 2026), Borealis has transitioned Sandman into an execution-focused phase, advancing engineering, metallurgy, and permitting in parallel to systematically derisk the project and progress it toward a buildable, development-ready gold operation.

Management commentary

"Following the results of our updated preliminary economic assessment, our focus at Sandman is now firmly on execution," said Kelly Malcolm, president and chief executive officer of Borealis. "We have initiated detailed engineering, drilling, metallurgical and permitting workstreams with the objective of advancing the project toward a construction decision. Importantly, we are well financed to complete this phase of work and systematically advance Sandman toward development.

"Sandman is a straightforward Nevada heap leach project with strong economics and a clear path to development. As our primary development asset, it complements our ongoing mining and production activities at the Borealis mine and represents the next stage of growth within our Nevada platform. Our priority is to define a buildable project, derisk the asset and position it for a disciplined transition into production."

Advancing toward a buildable Nevada gold operation

Borealis has engaged a group of leading engineering, technical and legal firms with extensive Nevada experience to support this next phase of advancement.

M3 Engineering & Technology Corp. has been engaged as lead engineering firm, responsible for overall co-ordination of engineering design and study activities. Respec Company LLC has been engaged to support mining, geology, resource modelling, hydrogeology, geotechnical work and environmental inputs to the integrated development plan.

Work programs under way and planned include:

• Comprehensive data verification and integration of historical and modern drilling data sets;
• Updated mineral resource modelling and validation;
• Geotechnical and hydrogeological characterization programs;
• Mine design optimization across the project's four deposits;
• Metallurgical testwork planning and execution;
• Process and infrastructure engineering, including heap leach and carbon handling systems;
• Capital and operating cost development.

These activities are designed to advance Sandman from a scoping-stage project toward a technically defined, buildable gold operation.

Permitting and environmental workstreams under way

In parallel with engineering activities, Borealis has initiated environmental baseline and permitting programs to support a clear pathway toward mine development.

The company has:

• Engaged Sunstone Environmental Solutions (Reno, Nev.) to advance environmental baseline studies;
• Retained Hunton Andrews Kurth LLP as United States permitting counsel to guide federal and state permitting strategy for Sandman and the Borealis mine.

These workstreams are focused on environmental data collection, regulatory engagement and permitting strategy development, positioning the project for efficient advancement through the permitting process.

Leveraging existing infrastructure for capital efficiency

Sandman benefits from Borealis's existing operational platform in Nevada, including its fully permitted Borealis mine and ADR (adsorption-desorption-recovery) processing facility; the Borealis ADR facility is approximately 220 miles from Sandman. Continuing engineering work includes evaluation of development scenarios that incorporate processing of loaded carbon at Borealis, with the potential to materially reduce initial capital requirements and accelerate a pathway to production.

Advancing toward production -- key milestones

Borealis is executing a series of parallel workstreams to systematically derisk Sandman and advance the project toward a construction decision. Key milestones include:

• Drilling programs:
  • Targeted drilling campaigns to support conversion of inferred mineral resources to measured and indicated categories, while also testing for resource expansion across the broader property.
• Metallurgical testwork:
  • Completion of column leach testwork and associated metallurgical programs to further define recoveries, reagent consumption and processing parameters at a development-ready level.
• Engineering and mine planning:
  • Advancement of detailed mine design, pit optimization, infrastructure layout and process engineering to support a technically robust, buildable operation.
• Environmental baseline studies:
  • Continuing baseline data collection, including hydrology, hydrogeology, geochemistry and biological studies, to support permitting and environmental assessment requirements.
• Permitting advancement:
  • Progression of federal and state permitting pathways, including early engagement with regulatory agencies and advancement of key permits required for construction and operations.
• Integrated development strategy:
  • Continued evaluation of development scenarios, including integration with Borealis's existing ADR facility, with the objective of optimizing capital efficiency and accelerating a potential path to production.

About the Sandman gold project

Sandman is a conventional open-pit, heap-leach gold project located in Humboldt county, Nevada, approximately 12 miles northwest of Winnemucca. The project hosts four known deposits -- North Hill, Silica Ridge, Southeast pediment and Abel Knoll -- and benefits from proximity to infrastructure and Borealis's existing operations.

A 2026 preliminary economic assessment (PEA) demonstrates robust project economics for a conventional, low-strip, heap-leach development scenario. At a base case gold price of $2,600 (U.S.) per ounce, the project generates an estimated after-tax net present value (6-per-cent discount rate) of approximately $203-million (U.S.) and an internal rate of return of approximately 105 per cent, with average annual production of approximately 38,000 ounces of gold over an approximately nine-year mine life. Life-of-mine gold production is estimated at approximately 340,000 ounces, with all-in sustaining costs of approximately $1,823 (U.S.) per ounce and initial capital of approximately $36-million (U.S.).

The PEA also highlights strong leverage to gold prices, with materially higher returns at prices above the base case.

The project is designed as a phased, capital-efficient development with the potential to utilize Borealis's existing ADR facility, providing a credible pathway toward reduced capital intensity and accelerated development.

Qualified person and cautionary statement

The scientific and technical information contained in this news release has been reviewed and approved by Kelly Malcolm, PGeo, president, chief executive officer and a director of the company, who is a qualified person as defined under National Instrument 43-101 -- Standards of Disclosure for Mineral Projects. Mr. Malcolm is not independent of the company.

The technical information relating to the Sandman gold project is based on the company's previously disclosed National Instrument 43-101 technical report titled "NI 43-101 Technical Report - Sandman Gold Property, Nevada, USA - Preliminary Economic Assessment," with an effective date of Jan. 5, 2026, and a report date of Feb. 19, 2026, prepared by Jerod Eastman, PGeo, an independent qualified person.

The PEA referenced herein is preliminary in nature and includes inferred mineral resources that are considered too speculative geologically to have economic considerations applied that would enable them to be categorized as mineral reserves. There is no certainty that the results of the PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

This news release contains references to continuing engineering, technical and permitting activities intended to advance the Sandman gold project. There is no certainty that such activities will result in the definition of mineral reserves, completion of a feasibility study or that the project will be placed into production. Advancement of the project is subject to a number of risks and uncertainties, including but not limited to technical results, permitting outcomes, availability of financing, commodity price fluctuations, and general economic and market conditions.

About Borealis Mining Company Ltd.

Borealis Mining is a gold mining and exploration company focused on the advancement of its Nevada-based assets, including continuing mining and production activities at the Borealis gold mine and the development of its Sandman gold project. The Borealis gold mine is a fully permitted mine site, equipped with active heap leach pads, an ADR facility and all necessary infrastructure to support a heap leach gold mining operation. In addition to the mine, the property, comprised 815 unpatented mining claims of approximately 20 acres each totalling approximately 16,300 acres and one unpatented mill site claim of about five acres located in western Nevada, is highly prospective for additional high-sulphidation gold mineralization. The Sandman project, previously acquired through the acquisition of Gold Bull Resources Inc., is an advanced exploration project with a recently completed (2021) National Instrument 43-101-compliant resource and a recent (2026) PEA which indicates compelling economics, particularly relative to the base case assumptions used in the study. Borealis is led by a strong board and management team, many of whom have founded, managed, and sold highly successful mining and exploration companies.

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