Selkirk Copper’s Minto mine update: resource, grade and restart lens for engineers
Reviewed by Joe Ashwell
First reported on MINING.com
30 Second Briefing
Resource update at Selkirk Copper Mines’ Minto project in Yukon outlines 47.8 million measured and indicated tonnes grading 0.89% copper, 0.34 g/t gold and 3.2 g/t silver, for 940 million lb. copper, 530,000 oz. gold and 4.8 million oz. silver, based on 428,388 metres of drilling in 1,956 holes. Contained measured and indicated copper has risen 181% versus 2025, albeit at lower grade as additional lower-grade tonnes are included, while inferred copper drops 48% to 281 million lb. at 0.76% Cu. The larger underground‑dominant resource, with about 45% open pit, is expected to underpin a Q3 feasibility study for a potential 2028 restart under Selkirk First Nation ownership.
Technical Brief
- Stage-one and historical drilling total 428,388 m from 1,956 holes underpin the new resource model.
- Stage-two infill/extension drilling is planned at 50,000 m, with 37,000 m already completed for further upgrades.
- Inferred inventory now sits at 16.9 Mt grading 0.76% Cu, 0.26 g/t Au and 2.7 g/t Ag.
- Contained inferred metal is 281 Mlb Cu, 142,000 oz Au and 1.5 Moz Ag after reclassification.
- Resource geometry is now underground-dominant, with only about 45% of tonnage considered open-pittable.
- Minto previously produced ~500 Mlb Cu between 2007 and 2023 before shutdown and receivership.
- Selkirk First Nation holds 18.2% of Selkirk Copper and became legal mine owner one year ago.
Our Take
With 940 million lb. contained copper in measured and indicated at the Minto project versus about 500 million lb. historically produced, Selkirk Copper is now working with an in-situ inventory that is nearly double past output, which typically underpins stronger financing and restart optionality for brownfield assets in Canada.
An 18.2% ownership stake for Selkirk First Nation in Selkirk Copper, combined with Minto’s Yukon location, positions this as one of the more substantial Indigenous equity positions in a producing-scale Canadian copper asset in our database, which is likely to influence permitting timelines and benefit-sharing structures for any restart plan.
Having about 45% of resources in open pit at grades near 0.9% copper is relatively high for Canadian open-pit copper in our coverage, suggesting that if a restart proceeds, early-phase scheduling could prioritise lower-strip, higher-margin tonnes to recover care-and-maintenance and restart costs more quickly.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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