Selkirk Copper Intersects 13.12% Copper Equivalent at Minto North, Phase 2 Ahead of Schedule

• Infill drilling at Minto North returned 6.01% copper, 8.77 grams per tonne (g/t) gold, and 36.6 g/t silver, or 13.12% copper equivalent, over 1.93 metres (m).
• That intercept lies within a broader interval grading 1.49% copper equivalent over 33 m.
• Step-out drilling at Minto North intersected mineralization beyond a previously interpreted fault, which indicates potential for expansion southward into an untested area.
• A 50-metre step-out at Area 118 returned 3.39% copper, 0.61 g/t gold and 16.5 g/t silver, or 3.73% copper equivalent, over 6.0 m.
• Phase 2 drilling has reached 45,299 m in 187 holes, or 90% of the planned 50,000 m.
• Selkirk Copper is targeting completion of a preliminary economic assessment (PEA) in the third quarter of 2026.

Company Overview

Selkirk Copper Mines (TSXV: SCMI | OTCQX: SKRKF | FRA: IO20) is advancing a restart and redevelopment plan for the former Minto copper-gold-silver mine in Yukon, Canada, in partnership with the Selkirk First Nation, which indirectly holds a controlling interest in the company. Selkirk Copper controls 26,850 hectares of mineral claims in the Minto-Carmacks copper belt, along with existing open-pit and underground infrastructure, including a 4,100-tonne-per-day processing plant and a 400-person camp.

Phase 2 Drilling Reaches 90% of Planned Meterage

The Phase 2 drill program at the Minto Project in Yukon, Canada, had completed 45,299 metres (m) in 187 holes as of August 18, 2026, or 90% of the planned 50,000 m. Four drill rigs are active on the program, which began on May 1, 2026, targeting expansion, exploration, and infill drilling of target areas, along with geotechnical data collection to support the upcoming feasibility study. The latest batch of results covers holes drilled in May, with laboratory turnaround for assays currently running at six to eight weeks.

President and Chief Executive Officer of Selkirk Copper Mines, M. Colin Joudrie, ties the latest intercepts to the zones the program was designed to expand:

"In a continuation of the positive drill results from the Phase 1 program, the Phase 2 program, led by the exploration and development team, continues to expand known zones of mineralization in the central mine area with very good grade copper-gold-silver intercepts over mineable widths at Minto North and Area 118."

Joudrie puts a number on the diamond drilling completed to date:

"In the last 11 months, Selkirk Copper has completed over 97,000 m of diamond drilling and is on track to exceed 100,000 m by the end of August."

Within the Phase 2 total, Area 118 and Minto Main account for the largest shares of the meterage, at 11,530 m and 10,069 m respectively.

High-Grade Copper, Gold & Silver in the Center of the 202 Lens

Infill drilling at Minto North targeted the 202 Lens, a high-grade zone delineated during the Phase 1 program, and all 4 holes intersected mineralization. The center of the lens returned 6.01% copper, 8.77 grams per tonne (g/t) gold, and 36.6 g/t silver, or 13.12% copper equivalent, over 1.93 m, within a broader interval of 1.49% copper equivalent over 33 m. The high-grade material is associated with semi-massive bornite and chalcopyrite, 2 copper sulfide minerals, and lies within a broader interval of strongly foliated rock containing bornite, chalcopyrite, and magnetite. The results further delineate the extent of high-grade mineralization within the lens and will help define the geometry of underground mining excavations.

Step-Out Drilling Points to a Faulted Extension South of Minto North

A hole testing the southern extents of the 202 Lens intersected 2 mineralized intervals. The lower interval confirmed the lens extent with the expected grade and thickness, returning 2.50% copper equivalent over 4.7 m. An upper interval that previous drilling had not anticipated returned 1.87% copper, 0.46 g/t gold, and 17 g/t silver, or 2.25% copper equivalent, over 13.3 m, including 3.43% copper, 0.36 g/t gold, and 47.0 g/t silver, or 3.87% copper equivalent, over 3.7 m.

A gouged and brecciated fault lies immediately below the upper interval, and a review of adjacent holes and surficial mapping indicates the fault has a reverse sense of displacement. Preliminary interpretation of the fault and the mineralization around it suggests the upper interval may represent the offset portion of the 202 Lens, which would extend the mineralized zone southward into an untested area.

Area 118 Step-Out Extends Mineralization 50 Metres Beyond Previous Drilling

Phase 2 drilling at Area 118 is targeting the expansion and delineation of several mineralized lenses near existing underground development. Three holes reported from the area intersected mineralization at depths between 150 and 350 m below surface, which confirms the modeled geometry of the lenses and increases confidence in grade estimation within them.

One of those holes, a 50-metre step-out beyond the limits of previous drilling and 125 m from historical underground development, returned 3.39% copper, 0.61 g/t gold and 16.5 g/t silver, or 3.73% copper equivalent, over 6.0 m, within a broader interval of 1.66% copper equivalent over 23.0 m. The hole intersected a thick interval of tightly folded, strongly foliated rock containing disseminated bornite and chalcopyrite, and the thickness and grade were better than expected. Mineralization in this area remains open to the southwest.

Grades Hold at Minto Main, Vary at Copper Keel

Follow-up drilling on the 117 Lens in the Minto Main area is a priority objective of the program, and all 4 holes reported there intersected mineralization with grade and thickness generally consistent with the 2026 mineral resource estimate for that location. A 30-metre step-out testing the western extents of known mineralization returned 0.98% copper, 0.39 g/t gold, and 3.4 g/t silver, or 1.25% copper equivalent, over 12.7 m, which indicates the lens remains open to the west.

At Copper Keel, 8 holes targeted infill of the eastern portion of the resource area, and 7 of them intersected copper-gold-silver mineralization. Assay grades were variable and somewhat lower than expected, ranging from 1.67% to 0.66% copper equivalent. The results confirm the continuity of the geological model at Copper Keel while indicating limited potential for additional resource expansion in that part of the deposit.

Preliminary Economic Assessment Work Advances

Selkirk Copper is advancing underground and surface mine development plans, integrated mine and mineral processing plans, waste storage facility designs, and facilities work, including capital, sustaining, and operating cost estimates, to inform a preliminary economic assessment (PEA). Work to fully incorporate the increase in the mineral resource estimate into the overall plans has required additional planning and development. The study will reflect the potential of a planned restart of the former Minto copper-gold-silver mine.

Next Steps

The drill program is targeting continuation until approximately late September, with assay results released through the summer and fall of 2026. Additional drilling is planned south of the 202 Lens at Minto North to confirm whether the upper interval represents the offset portion of the lens, and the team is evaluating further drilling on the 117 Lens to follow up on the western step-out.

Selkirk Copper is targeting completion of the PEA in the third quarter of 2026.

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