Highlights
Total Mineral Reserves of 5.83 million ounces of gold ("Moz Au") across its four operating assets.
Total Measured and Indicated Resources of 8.63 Moz Au1 and Inferred Resources of 2.5 Moz Au.
An initial underground Mineral Reserve of 0.44 Moz gold declared for Ledbetter Underground ("LUG"), Haile has removed lower margin open pit ounces while increasing asset Net Present Value ("NPV") by determining that Ledbetter will be best advanced as an underground mine.
Gold price assumption increased to a prudent $2,200/oz for reserves and $2,450/oz for resources.
Reserve additions were driven by open pit extensions at Macraes, supported by a higher gold price that extends mine life to 2032, and increases at the Horseshoe Underground at Haile.
At Wharekirauponga, 0.16 Moz of Inferred Resources was added, while a significant increase in resource conversion and growth drilling is planned for 2026.
NI 43-101 Technical Reports for Haile and Macraes will be released by March 31, 2026 providing updated life-of mine plans based on Mineral Reserves only. The Didipio NI 43-101 Technical report will be released in the first half of 2026.
Gerard Bond, President and CEO of OceanaGold, said "Our 2025 Reserves and Resources reflect the value added through our successful exploration efforts in 2025, particularly at Horseshoe Underground at Haile and Wharekirauponga Underground at Waihi. The technical work to convert the final open pit phase at Ledbetter to an underground Reserve at Haile resulted in increasing Haile's NPV. We are recognizing the benefits of operating in a higher gold price environment with the addition of 5 years mine life at Macraes, while maintaining a prudent $2,200 per ounce Reserve gold price assumption to ensure we produce profitable gold. We have a tremendous track record of organically growing our Reserve and Resources through exploration and we are increasing our investment in exploration by 50%, with a planned expenditure of $60M in 2026."
1. Measured and Indicated Mineral Resources are reported inclusive of Mineral Reserves.
Updated Mine Plans for Haile and Macraes
The updated Mineral Reserves for Haile reflects a change in mining method for the final Ledbetter open pit phase (Phase 4) to an underground mine. This change removes low-margin open pit ounces while improving the NPV of Haile. Beyond the economic benefits, the transition to underground also provides operational benefits, including significantly less waste movement, less rehandle, lower greenhouse gas emissions and lower tailings facility capacity requirements. In the upcoming technical report mine plan, LUG portal construction commences in 2028, with first development ore expected in 2029 and steady-state production expected in 2030. First ore from the Palomino Underground ("PUG") remains on schedule for 2028. Mine life for the site will be extended to 2036.
Haile is expected to produce on average 210,000 ounces of gold per year from 2027 through 2031, providing the mine a more sustainable, de-risked production profile as compared to the previous technical report. Notably, open pit mining continues at Haile across the other open pits until 2033, which remain part of the planned mining sequence in conjunction with the underground operation.
The increased reserves at Macraes reflects the leverage the mine has to a higher gold price, with previously marginal open pits becoming economic in a rising gold price environment, resulting in the addition of 5 years of reserve mine life. Applying a $2,200 gold price assumption (compared to $1,750 previously), additional open pit cutbacks were economic at Innes Mills, Coronation, Coronation North and Golden Bar, which, in conjunction with the Golden Point Underground, extends the mine life at Macraes to 2032.
Updated National Instrument 43-101, Standards of Disclosure for Mineral Projects ("NI 43-101") technical reports for Haile and Macraes will be filed on SEDAR+ by the end of March 2026 and will include life-of-mine plans, capital and costs estimates based on Mineral Reserves only. The Didipio NI 43-101 Technical report will be released in the first half of 2026.
Mineral Reserves
Mineral Reserves total 5.83 Moz, representing a net decrease of 0.39 Moz from the prior year (see Figure 1). The change was mainly driven by Haile, where reserves declined due to depletion and the change in mining method at LUG from an open pit to an underground mine, which removes lower margin open pit inventory while improving overall asset NPV. This was partially offset by additions at depth in the Horseshoe Underground. Additionally, higher gold price assumptions allowed for multiple new open pit phases at Macraes.
Notes:
"Depletion" refers to 2025 mining depletion.
"Reserve Model Updates" represent drilling and/or model updates to reserve or initial reserve declarations.
"Economic Factors" relate to gold price, mining cost and cut-off grade changes.
"Adjustments" relate to changes not captured in other categories. This includes the LUG mining method change.
The Proven and Probable Mineral Reserves estimates as at December 31, 2025 are presented in Table 1 below.
Table 1: Proven and Probable Reserves as at December 31, 2025
Proven
Probable
Proven & Probable
Gold
Tonnes (Mt)
Au (g/t)
Contained Ozs (Moz)
Tonnes (Mt)
Au (g/t)
Contained Ozs (Moz)
Tonnes (Mt)
Au (g/t)
Contained Ozs (Moz)
Haile
Horseshoe Underground
1.52
4.39
0.21
2.63
4.24
0.36
4.14
4.29
0.57
Palomino Underground
-
-
-
3.62
2.96
0.34
3.62
2.96
0.34
Ledbetter Underground
-
-
-
4.00
3.39
0.44
4.00
3.39
0.44
Open Pits
2.47
1.23
0.10
16.1
1.62
0.84
18.6
1.57
0.94
Haile Total
3.99
2.43
0.31
26.3
2.33
1.98
30.3
2.35
2.29
Didipio
Didipio Underground
13.5
1.39
0.60
14.7
0.85
0.40
28.3
1.11
1.01
Didipio Open Pit Stockpile
13.2
0.30
0.13
-
-
-
13.2
0.30
0.13
Didipio Total
26.7
0.85
0.73
14.7
0.85
0.40
41.5
0.85
1.13
Macraes
Macraes Underground
0.04
2.01
0.00
2.57
1.90
0.16
2.62
1.90
0.16
Macraes Open Pit
11.5
0.55
0.20
19.7
0.64
0.40
31.2
0.61
0.61
Macraes Total
11.5
0.56
0.21
22.3
0.78
0.56
33.8
0.71
0.77
Waihi
Martha Underground
-
-
-
3.43
3.85
0.42
3.43
3.85
0.42
Wharekirauponga
-
-
-
4.10
9.20
1.21
4.10
9.20
1.21
Waihi Total
-
-
-
7.53
6.76
1.64
7.53
6.76
1.64
Total Gold
42.3
0.92
1.25
70.9
2.01
4.58
113
1.60
5.83
Proven
Probable
Proven & Probable
Silver
Tonnes (Mt)
Ag (g/t)
Contained Ozs (Moz)
Tonnes (Mt)
Ag (g/t)
Contained Ozs (Moz)
Tonnes (Mt)
Ag (g/t)
Contained Ozs (Moz)
Haile
Horseshoe Underground
1.52
1.5
0.1
2.63
1.8
0.2
4.14
1.7
0.2
Palomino Underground
-
-
-
3.62
2.7
0.3
3.62
2.7
0.3
Ledbetter Underground
-
-
-
4.00
11
1.3
4.00
11
1.3
Open Pits
2.47
2.1
0.2
16.1
2.3
1.2
18.6
2.2
1.3
Haile Total
3.99
1.9
0.2
26.3
3.5
3.0
30.3
3.3
3.2
Didipio
Didipio Underground
13.5
1.7
0.7
14.7
1.3
0.6
28.3
1.5
1.4
Didipio Open Pit Stockpile
13.2
1.9
0.8
-
-
-
13.2
1.9
0.8
Didipio Total
26.7
1.8
1.6
14.7
1.3
0.6
41.5
1.7
2.2
Waihi
Martha Underground
-
-
-
3.43
17
1.9
3.43
17
1.9
Wharekirauponga
-
-
-
4.10
16
2.1
4.10
16
2.1
Waihi Total
-
-
-
7.53
17
4.0
7.53
17
4.0
Total Silver
30.7
1.8
1.8
48.6
4.9
