The project would yield an after-tax net present value of $263 million at a 5% discount rate and 40% internal rate of return at a $1,600/oz gold price following a $158 million initial capital cost.

KORE published a PEA on its Imperial project, also in California, in May.

"The Long Valley PEA is a key milestone towards KORE becoming a significant North American producer envisioning production of 250,000oz/y from our US projects," said CEO Scott Trebilcock.

The PEA outlined initiatives that may enhance the project including assaying silver in future drill programme to add silver into the resources, metallurgical testing to establish optimal crush size and cement addition, testing on very low-grade samples to determine viability of run-of-mine leaching, reviewing contract mining to reduce initial capital and drilling for more oxide resources.

Additional oxide mineralisation could extend the potential mine life, reduce capital intensity and generate higher project economic returns. KORE plans to drill-test the highest priority oxide and sulphide targets and is permitting drill pads.

Shares in KORE Mining are trading C$1.52, valuing the company at $133 million.