Mako Mining (TSXV: MKO) announced NI 43-101 Proven and Probable reserves of 597,744 oz Au and 6.30 Moz Ag at the Moss Mine in Arizona — 56.8 million tonnes at 0.327 g/t Au and 3.45 g/t Ag — with a post-tax NPV(5%) of US$254 million and a 15-year mine life. As a low-strip, heap-leach open pit, a sub-0.4 g/t reserve grade is not disqualifying the way it would be underground.
What deserves scrutiny is the price deck: the study assumes US$3,500/oz gold and US$50/oz silver. At a third of a gram per tonne, Moss is a price-taker — a large move in the gold assumption swings the NPV far more than at a high-grade project, because almost all of the margin is metal price rather than grade.
The reserve is legitimate and the mine life is long; the investment question is simply how comfortable you are underwriting US$3,500 gold for fifteen years. As disclosed in Mako's July 7, 2026 SEDAR+ filing.