Great Plains Metals intercepts 128 meters at Pencil Porphyry, Goodrich

Vancouver, BC, Canada – Tuesday, July 28, 2026 – TheNewswire - Great Plains Metals Corp. ("GPS" or "the Company", TSX-V: GPS, Frankfurt Exchange: 8VC) is very pleased to announce that the assay results confirm the discovery of a “pencil porphyry” at the Goodrich copper-gold project in New South Wales, Australia. Laboratory assays from drill hole GGDD004 have successfully verified a continuous, 128-meter intercept of porphyry-style mineralization. This broad intersection validates the Company’s porphyry exploration thesis: the historical, shallow Goodrich mine workings represent the upper tip of a multiphase, intact porphyry system.

Key Drill Highlights: Discovery Hole Intercept: Drill hole GGDD004 intersected 128 meters of mineralization with 0.34% copper and 0.17 g/t gold from 81.45m downhole. Mineralized Magmatic Cupola: A prominent high-grade zone right at the porphyry contact returned 3.55 meters @ 2.80% Cu and 0.18 g/t Au from 81.45m. Continuous Disseminated Chalcopyrite: Multiple sub-intervals dissected by post mineral dykes confirm continuous mineralization , including 26 meters @ 0.52% Cu and 0.24 g/t Au from 102m, and 5 meters @ 0.66% Cu and 0.49 g/t Au from 158m.

Near-Surface Depth: Importantly, the 128-meter mineralized intercept begins near-surface at just 81.45 meters depth. Technical Evaluation & Drill Hole Comparative Data The initial Phase One diamond drilling program was designed to test porphyry-style mineralization below the former Goodrich mine. Drill hole GGDD004 intersected significant disseminated copper and gold mineralization hosted in a monzonite porphyry stock (Figure 1).

Drill hole GGDD003 intersected altered monzonite porphyry representing the inner propylitic halo of the Goodrich porphyry (Figure 4). Table 1: GGDD004 Assay Results Figure 1. GGDD004 Drill Intersection.

Technical Analysis of Drill Hole GGDD004