Sandfire Resources America (SFR.V) has released an updated resource estimate on the Johnny Lee zone which is part of the company’s Black Butte copper project in Montana. Johnny Lee is formed by two separate mineralized zones (conveniently called the Upper Copper Zone and Lower Copper Zone) which are being permitted for production.
The updated resource now contains 10.9 million tonnes of rock in the measured and indicated resource categories with an additional 2.7 million tonnes at a 3% copper grade in the inferred resource category. On a combined basis, Johnny Lee now hosts approximately 800 million pounds of copper in an underground mine, a scenario where ASX-listed parent company Sandfire Resources (ASX:SFR) has plenty of experience considering its successful construction and operation of the DeGrussa mine in Australia.
The previous Preliminary Economic Assessment completed by the company is already 6.5 years old and perhaps it would be a good idea for SFR to consider putting out an updated study.
Disclosure: The author has no position in Sandfire Resources America.