Erdene Completes Transition to Gold Producer, Outlines District Development Plans

• First gold pour achieved at Bayan Khundii Mine in September 2025, ten years after initial discovery and five years after feasibility study completion
• Processing facility in month three of six-month startup phase, targeting steady-state production of 85,000 ounces annually by Q1 2026
• Reserves average 3.8 g/t gold with projected all-in sustaining costs under US$1,200 per ounce; Dark Horse South satellite pit averaging 7 g/t gold planned for 2027
• Over 5,000 metres drilled at Dark Horse and Altan Arrow with results expected Q1 2026; 3,000 metres completed at Khuvyn Khar copper targets
• Preliminary economic assessment scheduled for Q2 2026 on Zuun Mod molybdenum-copper deposit; mid-2026 drilling planned at Tereg Uul project

Erdene Resource Development Corp. (TSX:ERD) is a Canadian resource company that began gold production in 2025 at the Bayan Khundii Gold Mine in southwest Mongolia. The company operates Bayan Khundii through a 50:50 joint venture with Mongolian Mining Corporation. Erdene holds interests in multiple precious and base metal projects within the Khundii Minerals District, including gold-silver, copper-silver, and molybdenum-copper deposits. 

Bayan Khundii Gold Mine Production Ramp-Up and Operating Performance

Bayan Khundii achieved first gold pour in mid-September 2025, reaching production ten years after the first drill hole and five years following the feasibility study. The mine is operated by Erdene Mongol LLC, the joint venture between Erdene and Mongolian Mining Corporation. The operation is currently in month three of its six-month startup phase, with the processing facility performing in line with expectations according to management.

Initial production has utilised lower-grade material, with a planned transition to higher-grade ore as operations progress. The mine holds reserves averaging 3.8 g/t gold. A satellite reserve pit at Dark Horse South, averaging approximately 7 g/t gold, is scheduled for development in 2027. The mine has projected all-in sustaining costs of under US$1,200 per ounce.

CEO Peter Akerley stated:

"The Bayan Khundii mine is expected to ramp up to steady-state production by the end of the six-month startup period, delivering targeted annual gold production of approximately 85,000 ounces." 

Khundii Minerals District Multi-Mine Development Strategy

The Khundii Minerals District encompasses multiple deposit types across southwest Mongolia. Since 2009, Erdene has explored the area and assembled a portfolio including low sulphidation epithermal deposits at Bayan Khundii, intermediate sulphidation deposits at Altan Nar, porphyry-related copper-silver systems at Khuvyn Khar, and the molybdenum-copper Zuun Mod deposit. The company aims to develop a multi-mine, multi-commodity operation in the region.

Bayan Khundii is part of interconnected mineralised structures extending over more than 10 kilometres of strike length. Recent drilling has returned high-grade intersections to the west of the current pit. Early-stage drilling on the adjacent Ulaan licence has intersected high-grade, thick zones.

CEO Peter Akerley noted:

"Bayan Khundii is part of a network of interconnected mineralized structures extending over more than 10 kilometres of strike length, providing significant upside beyond the currently defined pit."

North of Bayan Khundii, the Dark Horse and Altan Arrow areas contain near-surface oxide gold and silver mineralisation. Over 5,000 metres of drilling was completed in this area, with results expected in Q1 2026. Metallurgical studies are underway to assess heap leach processing viability. The Altan Nar system, located northwest of current operations, hosts a high-grade gold-silver deposit that the company plans to advance through 2026.

2026 Exploration and Development Plans Across Portfolio Assets

At the Khuvyn Khar mining licence, 35 kilometres east of Bayan Khundii, over 3,000 metres of drilling was recently completed. Results are expected for the copper target and Zuun Mod deposit during Q1 2026. This area is 100% owned by Erdene. A preliminary economic assessment for the Zuun Mod molybdenum project is planned for Q2 2026, incorporating results from the recent drilling programme.

The company filed an updated mineral resource estimate for Zuun Mod in November 2025. The deposit contains molybdenum and copper mineralisation. The preliminary economic assessment will provide initial economic parameters for potential development.

Erdene has secured an option on the Tereg Uul project in southeastern Mongolia, located along trend from the Oyu Tolgoi copper-gold mine. Drilling is planned at this property in mid-2026. The company has stated plans to expand land holdings through acquisition, building on exploration success in the region.

Looking Ahead

The immediate priority is completing the Bayan Khundii startup phase and reaching steady-state production of 85,000 ounces annually. Exploration results from Dark Horse, Altan Arrow, and Khuvyn Khar are expected in Q1 2026. The Zuun Mod preliminary economic assessment is scheduled for Q2 2026. Drilling at Tereg Uul is planned for mid-2026. These activities form part of the company's stated objective to develop multiple mining operations across the Khundii Minerals District in southwest Mongolia.

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