🧾 What This Document Is

This is a National Instrument 43-101 Technical Report, a rigorous, independent study required for mining companies listed in Canada to publicly disclose the true value of their projects. Think of it as a comprehensive health check-up and appraisal for OceanaGold's Haile Gold Mine. It updates the official counts of gold in the ground and proves the mine is still a profitable business for years to come.

🏢 The Mine At A Glance

👉 In simple terms, the Haile Gold Mine is OceanaGold's cornerstone asset and the largest operating gold mine in the eastern United States. It's a complex operation combining large open pits with expanding underground mines, all feeding a single processing plant. Located in South Carolina, it has a rich history dating back to America's first gold rush in the 1820s.

⛏️ The Gold Inventory: Resources & Reserves

This is the core of the report—cataloging all the gold they know about and plan to mine.

Mineral Resources (The Broader Inventory): This includes all gold they've found, whether it's profitable to mine right now or not.

• Total Measured & Indicated Resources: 31.7 million tonnes at 2.67 grams of gold per tonne, containing 2.72 million ounces of gold.
• Inferred Resources (Less Certain): An additional 3.1 million tonnes at 2.4 g/t gold, containing 0.2 million ounces.

Mineral Reserves (The Bankable Gold): This is the gold that is economically and legally minable today. This is what the mine plan is built on.

• Total Proven & Probable Reserves: 30.3 million tonnes at 2.35 g/t gold, containing 2.29 million ounces.
  • This breaks down into 18.6 Mt from open pits (0.94 Moz) and 11.8 Mt from underground (1.35 Moz). 👉 Why it matters: The underground deposits have much higher gold grades (averaging 3.57 g/t) than the open pits (1.57 g/t). As the mine transitions from open pit to underground mining, the gold from each truckload of rock will be significantly richer.

⚙️ The Mine Plan & Timeline

The report outlines exactly how they will extract this gold over an 11-year mine life (until 2036).

• Production: The plan is to produce 1.9 million ounces of gold in total, averaging about 172,000 ounces per year during full production.
• The Transition: Open pit mining will wind down, while three underground mines (Horseshoe, Palomino, Ledbetter) will ramp up, becoming the primary source of ore by 2030.
• Processing: The existing plant can handle about 2.9 million tonnes of ore per year. A key upgrade to the "leach circuit" is planned for 2028 to efficiently recover gold from the tricky Ledbetter ore.

💰 The Money Story: Costs & Value

This section answers: "Will this mine make money?"

Capital Costs (Startup & Expansion Bills):

• Total LoM Capital: US$1.11 billion.
  • Sustaining CapEx: $574 million (to keep the current mine running).
  • Non-Sustaining CapEx: $539 million (for major new projects like building the Palomino & Ledbetter underground mines).

Operating Costs (The Bill to Run the Mine):

• Total Operating Cost: US$2.46 billion over the life of the mine, or about $80.93 per tonne of ore processed.
• Key Metric - AISC: The projected All-In Sustaining Cost (a key industry measure) is US$1,592 per ounce of gold. This includes mining, processing, site costs, and sustaining capital.

Economic Analysis (The Profitability Test): The report runs two financial models based on different gold prices:

1. At the Official "Reserve Price" (US$2,200/oz): The mine has an After-Tax Net Present Value (NPV) of US$414 million. It's still profitable at this conservative price.
2. At an "Alternative Price" (US$4,000/oz - closer to recent market): The value explodes. The After-Tax NPV becomes US$2.58 billion. 👉 Why it matters: The mine is solidly profitable at a conservative gold price. At higher, current prices, it becomes a massive cash flow generator. The project's value is highly sensitive to the gold price.

🔮 What's Next & The Big Picture

Future Outlook:

• Near-Term: Ramp up the Horseshoe underground and develop the Palomino underground. Complete the plant upgrade for Ledbetter ore by 2028.
• Strategic Move: A key decision was made to mine the Ledbetter deposit via underground methods instead of a planned open pit. A study showed this would be more profitable, reduce waste, and lower carbon emissions.
• Exploration: Work continues to find more gold near the existing mine ("near-mine exploration") to potentially extend the mine's life beyond 2036.

Strengths (👍) & Risks (⚠️):

• 👍 Strengths: Proven, large-scale operation. High-grade underground reserves. Existing infrastructure and permits. Generates strong cash flow.
• ⚠️ Risks: Geotechnical (slope stability) and water management challenges in the open pits. The Ledbetter ore requires a costly plant modification for good recovery. Future success depends heavily on gold prices and exploration success.

🧠 The Analogy

OceanaGold is managing a complex, multi-layered bakery with a shrinking, low-grade flour supply (open pits), but they've just discovered a hidden cellar stocked with premium, high-grade flour (underground mines). The report is their business plan: it shows how they'll use the old flour while building new ovens (plant upgrades) and logistics (mine development) to transition to baking premium, high-margin bread. The bakery's value will soar if the price of bread (gold) stays high.

📇 Key Contacts & People

Report Prepared By: OceanaGold Corp, Suite 1020, 400 Burrard Street, Vancouver, BC V6C 3A6 Canada.

Signed by Qualified Persons (QPs):

• David Carr, BEng Metallurgical (Hons), MAusIMM (CP) – Head of Metallurgy
• Gregory Hollett, BEng (Mining Engineering), P.Eng (EGBC) – Head of Mine Engineering
• Brianna Drury, BSc Mining Engineering, RM-SME – Underground Engineering Superintendent
• Jonathan Moore, BSc Geology (Hons), MAusIMM (CP) – Head of Resource Development
• Douglas Corley, BSc Geology (Hons), MAIG (RPGeo) – Principal Geologist, Resource Development
• Larry Standridge, PE, MSE Geotechnical – Principal Engineer, Call & Nicholas
• Robert Cook, PE, RM-SME – Principal II Geological Engineer, Call & Nicholas
• Jay Newton Janney-Moore, PE, RM-SME – Senior Project Manager I, NewFields
• William Lucas Kingston, MSc, PG, RM-SME – Senior Hydrogeologist, NewFields
• Brooke J. Miller, MSc., CPG – Principal Consultant, Geology, SRK

🧩 Final Takeaway

This report confirms that OceanaGold's Haile Mine is a long-life, profitable operation with a clear plan to transition to high-grade underground mining. While it requires significant upfront investment, its substantial value—especially at today's gold prices—is firmly established in this independent blueprint for the next decade.