Updated PFS for the Johnny Lee Deposit and new Mineral Resource estimate for the nearby Lowry Deposit underline the high-grade underground copper potential, with a Probable Mineral Reserve for the Johnny Lee Deposit of 9.5Mt at 2.9% Cu for 270,000t of copper and an 8-year life at the Black Butte Copper Project in Montana, USA, that aligns with the stringent Mine Operating Permit conditions.  WHITE SULPHUR SPRINGS, Mont., Dec. 16, 2025 (GLOBE NEWSWIRE) -- Sandfire Resources America Inc. (“Sandfire America” o ...