Omai Gold Reports 92% Increase in Total Mineral Resources to 6.5 Million Ounces

• Total mineral resources increased 92% to 4.4 million ounces (Inferred) and 2.1 million ounces (Indicated) across both deposits
• Wenot deposit Inferred resources grew 130% to 3.7 million ounces at 1.82 g/t Au from additional drilling
• Gold price assumption raised to $2,500/oz from $1,850/oz, enabling lower 0.30 g/t cut-off grade from 0.35 g/t
• Gilt Creek deposit contains 1.15 million Indicated ounces at 3.22 g/t Au for underground mining approach
• Updated Preliminary Economic Assessment scheduled for late 2025 incorporating both deposits

Omai Gold Mines Corp. (TSXV: OMG) (OTCQB: OMGGF) is a Canadian gold exploration and development company focused on expanding two orogenic gold deposits at its 100%-owned Omai Gold Property in Guyana. The company has established mineral resources at the Wenot shear-hosted deposit and the Gilt Creek intrusive-hosted deposit within the Guiana Shield greenstone belt.

The Omai Gold Project utilises existing infrastructure from the historical Omai Mine that produced 3.7 million ounces from 1993 to 2005, when operations ceased at gold prices below $400 per ounce. The site includes road access, an airstrip, cleared areas, and established tailings facilities. The property will connect to Georgetown and Linden via paved road infrastructure.

Updated Mineral Resource Estimate Results

The August 2025 mineral resource estimate incorporates 36 new diamond drill holes totalling 23,597 metres at the Wenot deposit, bringing total drilling to 639 holes with 12,028 assay results. Total combined resources across both deposits reached 6.5 million ounces, with Wenot contributing 4.7 million ounces and Gilt Creek adding 1.8 million ounces. The Wenot Inferred category increased from 1.6 million to 3.7 million ounces.

The updated estimate reflects current economic parameters with gold price assumptions increased to $2,500 per ounce from $1,850 per ounce. This adjustment enabled cut-off grade reductions from 0.35 g/t to 0.30 g/t for fresh rock, incorporating previously sub-economic material. Operating cost assumptions were also updated to reflect current conditions, with open pit mining costs of $2.50/t for mineralised material and $2.00/t for waste.

Approximately 60% of the Wenot mineral resource estimate sits above 350 metres depth from surface, with 30% located west of the historical open pit. The deposit remains open in all directions along a minimum 2.5-kilometre length of the host Wenot shear corridor. Five additional drill holes have been completed after the cut-off date with assays pending for future resource updates.

Deposit Characteristics and Development Plans

The Wenot deposit hosts gold mineralisation within shear-controlled zones averaging 1.82 g/t Au (Inferred) and 1.46 g/t Au (Indicated). Mining methodology combines open pit extraction for near-surface material and underground methods for deeper, higher-grade zones. The deposit demonstrates geological continuity with mineralised widths typically ranging 20-50 metres in the main corridors.

The Gilt Creek deposit sits within the "Omai Stock" quartz-diorite intrusive, 500 metres north of Wenot and below the past-producing Fennel open pit. The deposit contains 1.15 million Indicated ounces at 3.22 g/t Au and 665,000 Inferred ounces at 3.35 g/t Au, located primarily between 280-600 metres depth. The intrusive previously produced approximately 2.4 million ounces from the upper 250 metres through historical mining operations.

Recent drilling at Gilt Creek, including hole 24ODD-095 extending 1,185 metres, continued to intersect gold mineralisation 200 metres beyond previously interpreted boundaries. The deposit features sub-horizontal mineralised zones within a 500m by 300m intrusive body. Underground mining approach applies due to depth and grade characteristics, with metallurgical recovery assumptions of 92% based on historical performance.

Economic Assessment and Development Timeline

The company has commenced work on an updated Preliminary Economic Assessment incorporating both the expanded Wenot resource and the Gilt Creek deposit, scheduled for completion in late 2025. The baseline April 2024 PEA covered only limited Wenot open pit operations, projecting 1.84 million ounces production over 13 years with after-tax NPV5% of $556 million and 20% IRR at $1,950/oz gold price.

The updated assessment will evaluate a combined development scenario including an expanded Wenot open pit operation with subsequent underground mining for higher-grade zones. Concurrent surface access development will enable Gilt Creek underground mining commencing at approximately 280 metres depth. The mine plan incorporates both deposits' distinct geological and grade characteristics.

Current exploration continues with three drill rigs operating on resource expansion, grade upgrade drilling, and satellite deposit identification. Two rigs focus on near-surface satellite deposits whilst the third continues deep drilling to test expansion potential below the Gilt Creek deposit. Work progresses toward an eventual Feasibility Study planned for later in 2026, subject to successful completion of the updated PEA.

Development Outlook

Omai Gold has increased total mineral resources to 6.5 million ounces through systematic drilling and updated economic parameters. The company plans to complete an updated Preliminary Economic Assessment by late 2025 incorporating both deposits in a unified development plan. Continued drilling targets resource expansion and category upgrades, with results from five completed holes pending inclusion in future resource updates. The progression toward feasibility study work depends on successful completion of the updated economic assessment and continued resource growth.

‍