OceanaGold Announces Ongoing Exploration Success at Haile
VANCOUVER, BC, Sept. 11, 2025 — OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) (“OceanaGold” or the “Company”) is pleased to announce positive results from its exploration and resource conversion drilling programs at the Haile Gold Mine (“Haile”) in the United States.
Gerard Bond, President and CEO of OceanaGold, said: “With a record high exploration budget of $10 million at Haile this year, we are delighted by the excellent return on investment we continue to generate through exploration. These exciting results continue to demonstrate the continuity of high-grade mineralization at several deposits across the property, notably at Ledbetter Phase 4, Horseshoe Underground, and the promising new early-stage Pisces and Clydesdale targets. The exploration success continues to highlight the exceptional upside for low-risk organic growth we have within our existing portfolio of assets.”
Drilling highlights (core length)
Ledbetter Phase 4 (conversion drilling)
- 28.9 m @ 18.33 g/t Au (DDH1279)
- 8.7 m @ 22.30 g/t Au (DDH1281)
Horseshoe (conversion drilling)
- 16.1 m @ 16.33 g/t Au (UGD0082)
- 14.6 m @ 10.33 g/t Au (UGD0084)
- 24.0 m @ 7.99 g/t Au (UGD0085)
- 22.0 m @ 8.60 g/t Au (UGD0086)
- 10.2 m @ 11.12 g/t Au (UGD0084)
Pisces (initial drilling; ~300 m south of Horseshoe)
- 7.6 m @ 10.39 g/t Au (DDH1271)
- 6.6 m @ 3.34 g/t Au (DDH1290)
Clydesdale (initial drilling; ~100 m NW of Palomino)
- 26.2 m @ 4.11 g/t Au (DDH1282)
Interactive 3D results and a visual representation of the drill hole locations are available via VRIFY: https://vrify.com/meetings/recordings/c880f1e8-449e-41a1-916c-125c8df72661.
Ledbetter Phase 4 — underground conversion potential
Ledbetter Phase 4 mineralization occurs within the final phase of the open pit Mineral Reserve. A resource conversion drill program (four holes, ~1,975 m) has returned strong intersections including 28.9 m @ 18.33 g/t Au from 489.1 m (including 1.3 m @ 189.22 g/t) and 8.7 m @ 22.30 g/t Au from 375.9 m (including 5.0 m @ 35.86 g/t). The program is supporting metallurgical testing and a trade-off study to evaluate potential underground development at Ledbetter.
Horseshoe Underground — continued resource growth
Drilling at Horseshoe has focused on both conversion and definition work. Since the February 2025 update, 24 holes totaling 7,467 m were completed. Conversion drilling (14 holes, 4,261 m) targeted Inferred resources in lower levels with notable intercepts listed above. Definition drilling (10 holes, 3,206 m) targeted step-outs to the south and west; assays for nine holes include 7.6 m @ 3.63 g/t and 9.1 m @ 3.40 g/t (UGD0097) and 5.0 m @ 5.64 g/t (UGD0100). The definition program remains ongoing with ~2,600 m to be drilled in 2025.
Pisces — new high-grade target near infrastructure
Pisces lies on the corridor between Horseshoe and Palomino, ~550 m below surface and close to existing/planned underground infrastructure. Nine holes (6,167 m) were drilled in 2025 testing continuity; significant intercepts include 7.6 m @ 10.39 g/t Au (DDH1271) and 6.6 m @ 3.34 g/t Au (DDH1290). Previously reported high-grade results (e.g., 44.2 m @ 10.85 g/t Au, 9.4 m @ 44.14 g/t Au) define a ~150 m strike of higher-grade mineralization that remains open to the northeast and down-dip.
Clydesdale — successful early-stage result
Clydesdale is an early-stage target ~100 m NW of Palomino and ~300 m stratigraphically lower (~800 m below surface). Two holes (~1,600 m) were completed in 2025, returning 26.2 m @ 4.11 g/t Au from 780.7 m, including 14.6 m @ 6.21 g/t (DDH1282). Two additional holes are planned to bring the 2025 total to ~1,800 m.
Quality assurance / Qualified person
The technical information in this release has been reviewed and approved by Craig Feebrey, Member of the Australasian Institute of Mining and Metallurgy and a qualified person under NI 43-101. From July 2017 to 2025 nearly all Haile exploration core samples were prepared at ALS Tucson and analyzed at ALS Reno, independent of OceanaGold; select samples were prepared and analyzed at SGS Kershaw, South Carolina in 2025 with confirmation duplicates sent to ALS Reno. ALS and SGS are ISO 17025 certified. Standard QA/QC procedures (blanks, standards, duplicates) are applied and handled by the OceanaGold geology team.
Technical reports and further information
For additional drill hole data, please refer to: https://investors.oceanagold.com/additional-drillhole-data.
The NI 43-101 technical report “NI 43-101 Technical Report Haile Gold Mine, Lancaster County, South Carolina” (effective date December 31, 2023; report dated March 28, 2024) is available on SEDAR+ at www.sedarplus.com and on the Company’s website at www.oceanagold.com.
About OceanaGold
OceanaGold is an intermediate gold and copper producer focused on safely and responsibly maximizing free cash flow and delivering returns for shareholders. Operating mines include Haile (United States), Didipio (Philippines), and Macraes and Waihi (New Zealand).
Cautionary statement
This release contains forward-looking statements regarding future exploration, potential resource growth, timing and costs of development, and other expectations. Forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially. See the Company’s filings on SEDAR+ and its website for more information; readers should not place undue reliance on forward-looking statements.
Source: OceanaGold Corporation