Miller Copper-Gold Property

• Two Complementary Copper-Gold Exploration and Development Opportunities in the Kirkland Lake Mining Camp

  

  Northstar Gold Corp.’s 100%-owned Miller Copper-Gold Property, located approximately 18 kilometres southeast of Kirkland Lake, Ontario, hosts two distinct and potentially complementary opportunities: the high-grade Cam Copper VMS Project, currently being advanced toward potential development utilizing Surgical Mining™ technology, and the Allied Gold Zone, a large, near-surface alkalic intrusion-hosted gold system with significant expansion potential.

  Northstar has systematically explored the Miller Property with diamond drilling, surface stripping and sampling, together with property-wide IP, gravity, magnetic and electromagnetic surveys. This work has established two principal centres of mineralization and two potential pathways for creating value from the Property.

• CAM COPPER – HIGH-GRADE COPPER DEVELOPMENT & VMS EXPLORATION

  Located approximately 2.5 kilometres southwest of the Allied Gold Zone, the historic Cam Copper Mine is a road-accessible, high-grade copper-gold-silver VMS system and Northstar’s principal critical minerals development opportunity. Cam Copper is one of three proximal historic copper shaft mines and small-scale past producers situated along the Boston Creek Copper Belt.

  Northstar drilling has confirmed a high-grade, polymetallic VMS system at Cam Copper, with the near-surface Zone 2 forming the initial focus for potential development. A 2025 Exploration Target Study outlined a conceptual 75,000 to 140,000 tonnes grading 9% to 18% Cu, with a conceptual average grade of 12% Cu. Zone 2 remains open at depth and plunges southeast along a well-defined VMS feeder structure.

  Recent definition drilling has significantly advanced the geological model. A seven-hole, 1,204-metre program completed in late 2025 confirmed pronounced down-plunge continuity and discovered a new polymetallic Cu-Au-Ag-Mo domain approximately 50 metres down plunge from the previously reported 14.8% Cu over 2.45 metres intercept. Hole CC-25-14 returned 3.05% Cu, 5.9 g/t Au, 22.9 g/t Ag and 0.45% Mo over 3.07 metres, while deeper drilling in CC-25-16 intersected high-grade bornite grading 13.95% Cu, 0.62 g/t Au and 32 g/t Ag over 0.56 metres.

  The drilling indicates a steeply plunging VMS feeder system with increasing size and gold grade at depth, characterized by stacked sulphide lenses and polymetallic metal zonation. Northstar interprets the expanding gabbro bodies and increasing metal endowment at depth as supporting the potential for additional high-grade Cu-Au-Ag-Mo mineralization along the down-plunge extension of Zone 2.

  Advancing Toward Surgical Mining

  Northstar is advancing Cam Copper as the principal demonstration and validation site for the Surgical Mining for Critical Minerals Project, in collaboration with Novamera Inc., Micon International Limited and DIGITAL. The approximately $11 million consortium initiative has been approved for access to up to $4 million in DIGITAL co-investment funding.

  The project is evaluating Novamera’s proprietary Surgical Mining™ technology to selectively extract high-grade Zone 2 mineralization using large-diameter drilling, real-time downhole imaging, data analytics and immediate backfilling. Current work includes geological and block model updates, metallurgical testing, preparation of an NI 43-101 Technical Report and Mineral Resource Estimate, permitting, detailed engineering, mine planning and site preparation.

  Exploration Upside Beyond Zone 2

  The Cam Copper opportunity extends well beyond the initial Surgical Mining target. High-grade Zone 2 mineralization remains open down plunge, while recent drilling and geophysics have identified additional VMS horizons and targets extending approximately one kilometre southeast of the historic mine.

  Northstar’s broader exploration program has discovered a 500-metre-long stratiform horizon anomalous in zinc and gold, a separate 15.76-metre-thick copper-bearing horizon, and new Zone 1 copper mineralization southeast of the historic workings. Together with the strengthening polymetallic Zone 2 system at depth, these results provide multiple opportunities to expand the known Cam Copper VMS system along strike, down plunge and through the discovery of additional parallel mineralized horizons.

  Explore the Cam Copper Project

• ALLIED GOLD ZONE – LARGE-SCALE GOLD EXPLORATION & EXPANSION OPPORTUNITY

  The Allied Gold Zone is an advanced, near-surface alkalic intrusion-hosted gold-telluride system situated within the Miller Intrusive Complex. Northstar drilling has defined broad zones of near-surface gold mineralization accompanied by higher-grade gold-copper structures, with the system remaining open along strike, down dip and at depth.

  An independent 2022 SRK Consulting Exploration Target Study outlined a conceptual exploration target of approximately 250,000 to 500,000 ounces of gold, with estimated grades ranging from approximately 1.4 to 2.04 g/t Au.*

  Drilling has returned numerous broad gold intercepts, including:

  • 6.6 g/t Au over 117.0 metres
  • 4.0 g/t Au over 50.6 metres
  • 1.43 g/t Au over 118.5 metres
  • 1.2 g/t Au over 107.3 metres

  Higher-grade gold-copper feeder-style structures have also been intersected, including 4.71 g/t Au and 0.51% Cu over 6.4 metres and 9.41 g/t Au and 1.03% Cu over 3.0 metres.

  A high-resolution UAV magnetic survey subsequently identified a large magnetic anomaly, designated SM-01, extending to greater than one kilometre depth beneath the Allied Gold Zone. Northstar interprets this anomaly as a possible deeper intrusive source to the near-surface gold system, providing an important target for future exploration of the Miller Intrusive Complex.

  Beyond Allied, multiple additional syenite-associated gold targets occur throughout the Miller Intrusive Complex, providing further opportunities to expand the known mineralized system.

  Explore the Allied Gold Zone

• ONE PROPERTY – TWO PATHWAYS FOR GROWTH

  The Miller Copper-Gold Property provides Northstar with two complementary opportunities at different stages of advancement:

  Cam Copper provides a high-grade critical minerals opportunity with a defined conceptual Exploration Target, an advancing Surgical Mining™ development pathway and significant VMS exploration upside along strike and at depth.

  Allied Gold provides a substantially larger-scale gold exploration opportunity with an established conceptual Exploration Target, broad near-surface gold mineralization and multiple opportunities for expansion within the larger Miller Intrusive Complex.

  Together, Cam Copper and Allied Gold provide Northstar with a strategy to pursue near-term high-grade copper development while continuing to evaluate and expand the larger-scale gold potential of the Miller Copper-Gold Property.

  * The above Exploration Targets range in tonnes and grade highlights the exploration potential of Cam Copper No. 2 Zone and the Allied Gold Zone. The quantity and quality are purely conceptual in nature. Insufficient exploration has been carried out to define a mineral resource on the property and a Qualified Person has not done sufficient work to classify the Exploration Target projections as current mineral resources. These values cannot and should not be relied upon are only included herein as an indication of potential mineralization on the Property. Additional exploration including a 43-101 Technical Report, CIM and NI-43-101 reporting compliant mineral resource estimate and Preliminary Economic Assessment are required to establish the economic potential of Cam Copper No. 2 and Allied Gold Zones. It remains unclear whether a mineral resource will be delineated on the Property.