Lion Copper’s Yerington copper portfolio: scale, capex and PFS lens for mine planners
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
Lion Copper & Gold’s Bear deposit at the Rio Tinto-backed Yerington project in Nevada has an initial resource of about 1.0 billion indicated tonnes at 0.29% copper (6.7 billion lb) and 1.7 billion inferred tonnes at 0.22% copper (8.7 billion lb), making it one of the state’s largest undeveloped copper resources. Combined with Yerington’s 506.6 million tons of proven and probable reserves at 0.21% copper (2.1 billion lb), Lion’s Nevada portfolio now totals roughly 19 billion lb of contained copper, surpassing Hudbay’s Mason and Pumpkin Hollow. A 2025 PFS outlined 120 million lb/year cathode output over 12 years, with a post-tax NPV7 of US$694 million, 14.6% IRR and US$724 million initial capex, while Rio Tinto’s Nuton continues heap-leach testing under its 65% earn-in option.
Technical Brief
- Bear deposit lies within the Rio Tinto-backed Yerington district, ~34 km west of Carson City.
- Resource upgrade at Bear is explicitly intended to support further engineering studies and mine planning.
- Lion Copper flags additional drilling at Bear as the key lever to convert and expand inferred tonnage.
- Yerington’s proven and probable reserve figure explicitly includes the MacArthur deposit within the same project area.
- Both Bear and Yerington fall under Rio Tinto/Nuton’s option-to-earn 65% interest via a new project company.
- Nuton’s proprietary heap-leach technology has been under test at Yerington since 2022, targeting sulphide leachability.
- The same Nuton leach flowsheet is already in commercial use at Gunnison Copper’s Johnson Camp mine in Arizona.
- Market reaction to the Bear resource update saw Lion Copper’s share price drop 24% to C$0.22, capitalising it at C$94.9 million.
Our Take
Rio Tinto’s Nuton has already demonstrated commercial-scale sulphide bioleaching at Gunnison Copper’s Johnson Camp mine in Arizona, and the AWS offtake deal there signals that copper cathode from Yerington using the same technology could be positioned for premium, low-carbon supply contracts rather than just selling into the spot market.
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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