Trilogy–South32 Arctic copper permit push: design and geotech notes for engineers
Reviewed by Tom Sullivan

First reported on MINING.com
30 Second Briefing
Trilogy Metals and South32’s 50/50 Ambler Metals JV has approved a $35 million 2026 work programme at Alaska’s Upper Kobuk Mineral Projects, targeting mine-permit submissions for the high-grade Arctic copper deposit under federal FAST-41. Drilling will focus on geotechnical and condemnation holes for mine design and infrastructure siting, while the Bornite camp is upgraded for multi-year geotechnical and exploration campaigns and an independent UKMP management team is re-established. Arctic’s 2023 feasibility study outlines a 13-year operation producing 149 Mlb/y copper plus zinc, lead, gold and silver, with an after-tax NPV8 of $1.1 billion and 22.8% IRR.
Technical Brief
- Trilogy has separately budgeted about $5 million for corporate compliance and oversight of the Ambler JV.
- US government has injected $35.6 million into Ambler Metals to support Upper Kobuk Mineral Projects development.
- Reinstated permits for the 340 km Ambler Road re-open surface access planning for mine logistics and construction.
- Arctic and Bornite sit within a 1,900 km² land package in Alaska’s Ambler mining district, constraining infrastructure corridors.
Our Take
South32’s push with copper and zinc at the UKMP in Alaska comes as our database also shows it exiting or mothballing higher‑cost aluminium and ferronickel assets like Mozal and Cerro Matoso, signalling a portfolio tilt towards long‑life base‑metal sulphide systems.
At over 5% copper‑equivalent grade and with both Arctic and Bornite showing double‑digit IRRs, the Ambler Mining District assets sit at the higher‑margin end of copper projects in our recent coverage, which could help offset the permitting and infrastructure risk tied to the 340 km Ambler Road.
With copper and zinc among the most frequently tagged commodities in our 378 Mining stories, a permitted UKMP hub in north‑western Alaska would add a rare US‑domiciled, multi‑metal camp to a project pipeline otherwise dominated by Latin American and African copper entries in our database.
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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