Orla Mining Delivers Initial Underground Mineral Resource for Camino Rojo in Mexico, Paving the Way for Future Development Planning

2025-06-05

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3.95 Moz Measured & Indicated & 0.40 Moz Inferred Gold Mineral Resources

VANCOUVER, BC , June 5, 2025 /CNW/ - Orla Mining Ltd. (TSX: OLA) (NYSE: ORLA) ("Orla" or the "Company") is pleased to provide the first underground Mineral Resource estimate for the Company's Camino Rojo deposit located in Zacatecas, Mexico , representing a down plunge extension from the oxide open pit.

This news release presents the initial underground Mineral Resource estimate for the Camino Rojo deposit, incorporating mineralization hosted in the Camino Rojo Sulphides and extending into the underlying Zone 22 (Figures 1, 2a). Zone 22 represents the vertical and down plunge continuation of the Camino Rojo sulphide mineralization.

Summary Highlights:

Measured and Indicated Mineral Resource: 50.1 Mt at 2.45 g/t Au, 10.6 g/t Ag, and 0.25% Zn, averaging 2.58 g/t AuEq, totaling 3.95 Moz Au , 17.05 Moz Ag , 278 Mlbs Zn, and 4.16 Moz AuEq.

Inferred Mineral Resource: 5.6 Mt at 2.21 g/t Au, 10.9 g/t Ag, and 0.21% Zn, averaging 2.33 g/t AuEq, totaling 0.40 Moz Au , 1.95 Moz Ag , 26 Mlbs Zn, and 0.42 Moz AuEq .

Zone 22 accounts for only 7% (0.29 Moz AuEq) of the current underground Indicated Mineral Resource and 19% (0.08 Moz AuEq) of the current underground Inferred Mineral Resource. This represents only a portion of the defined mineralization in Zone 22, with drilling ongoing. The 2025 drilling results from Zone 22 will be incorporated in future resource updates.

Recovery model supported by ongoing metallurgical work: The mineral resource is divided into three spatially distinct zones, each with specific processing options for the Caracol-hosted mineralization: heap leaching (3%); cyanidation (CIL) (25%); and flotation followed by pressure oxidation ("POX") as a pre-treatment prior to cyanidation (CIL with POX) (72%). These zones inform the resource recovery assumptions. Initial metallurgical testing indicates that material from Zone 22 is amenable to both cyanide leaching and flotation.

Development strategy to advance the initial underground Mineral Resource towards possible future construction decision. This includes additional exploration, development planning for an exploration drift to allow for tighter spaced underground drilling, flowsheet design, further metallurgical testing, engineering studies, and permitting activities.

"This initial underground resource marks an important milestone at Camino Rojo. When we acquired the project, the scale of the mineralized system was clear, but the path forward was uncertain. This resource crystallizes our belief in the potential for a future underground operation. Our team has taken a systematic approach, and we will now look to increase confidence and establish a clear path to construction."

– Jason Simpson , President and CEO

"Over the past few years, our efforts have focused on drilling the sulphide zone, improving the geological model, and extending mineralization down-plunge in the newly discovered Zone 22. We have now delivered a significant initial underground resource, a key milestone that will inform an upcoming Preliminary Economic Assessment and establish the foundation for potential long-term production at Camino Rojo. The deposit remains open down plunge and at depth, and we remain committed to continued exploration and unlocking the full potential of Camino Rojo."

– Sylvain Guerard , Senior Vice President, Exploration

Initial Underground Camino Rojo Mineral Resource Estimate:

The underground resource, including the Camino Rojo Sulphides and Zone 22, extends from the base of the oxide pit to approximately 1,200 metres below surface (or up to 1,300 metres down plunge from the pit base), covering up to one kilometre along strike and 200 to 400 metres in width (Figures 2a, 2b , 3).

The Mineral Resource estimate, prepared by SLR Consulting ( Canada ) Ltd, includes a resource panel constrained Measured and Indicated Mineral Resource totalling 50.1 Mt at 2.45 g/t Au, 10.6 g/t Ag and 0.25% Zn, equating to 2.58 g/t AuEq. Contained metal amounts to 3.95 Moz gold, 17.05 Moz silver and 278 Mlbs zinc, totalling 4.20 Moz AuEq.

The Inferred Mineral Resource totals 5.6 Mt at 2.21 g/t Au, 10.9 g/t Ag and 0.21% Zn, equating to 2.33 g/t AuEq. Contained metal amounts to 0.40 Moz gold, 1.95 Moz silver and 26 Mlbs zinc, resulting in a total of 0.42 Moz AuEq. See Table 1 and Figures 4 to 6 for details.

The Mineral Resources reported for Zone 22 are constrained within underground resource panels below the Caracol Formation, which represent the vertical and down plunge continuation of the Camino Rojo sulphide mineralization. Zone 22 has been drilled to nearly one kilometre below the Caracol Formation and remains open at depth and down-plunge.

Table 1: Camino Rojo Underground Mineral Resource Estimate:

| | | | | | | | | | | | | | | | Descriptions | | Measured | Indicated | Measured & Indicated | Inferred | | | | | | | | | | | | kt | g/t | koz | kt | g/t | koz | kt | g/t | koz | kt | g/t | koz | | GOLD (Au) | Heap leach | 7 | 1.95 | 0 | 1,704 | 2.90 | 159 | 1,711 | 2.90 | 159 | 214 | 2.29 | 16 | | | CIL | - | - | - | 12,475 | 2.07 | 832 | 12,475 | 2.07 | 832 | 2,549 | 1.81 | 148 | | | FLOT/POX/CIL | - | - | - | 35,900 | 2.56 | 2,958 | 35,900 | 2.56 | 2,958 | 2,813 | 2.57 | 232 | | | Total - Gold | 7 | 1.95 | 0 | 50,079 | 2.45 | 3,949 | 50,086 | 2.45 | 3,950 | 5,576 | 2.21 | 396 | | | | kt | g/t | koz | kt | g/t | koz | kt | g/t | koz | kt | g/t | koz | | SILVER (Ag) | Heap leach | 7 | 31.5 | 7 | 1,704 | 13.2 | 722 | 1,711 | 13.3 | 729 | 214 | 15.1 | 104 | | | CIL | - | - | - | 12,475 | 8.7 | 3,480 | 12,475 | 8.7 | 3,480 | 2,549 | 10.2 | 835 | | | FLOT/POX/CIL | - | - | - | 35,900 | 11.1 | 12,847 | 35,900 | 11.1 | 12,847 | 2,813 | 11.2 | 1,010 | | | Total - Silver | 7 | 31.5 | 7 | 50,079 | 10.6 | 17,048 | 50,086 | 10.6 | 17,055 | 5,576 | 10.9 | 1,949 | | | | kt | % | Mlb | kt | % | Mlb | kt | % | Mlb | kt | % | Mlb | | ZINC (Zn) | Heap leach | - | - | - | - | - | - | - | - | - | - | - | - | | | CIL | - | - | - | - | - | - | - | - | - | - | - | - | | | FLOT/POX/CIL | - | - | - | 35,900 | 0.35 | 278 | 35,900 | 0.35 | 278 | 2,813 | 0.42 | 26 | | | Total - Zinc | 0 | 0 | 0 | 35,900 | 0.35 | 278 | 35,900 | 0.35 | 278 | 2,813 | 0.42 | 26 | | | | kt | g/t | koz | kt | g/t | koz | kt | g/t | koz | kt | g/t | koz | | AUEQ (Au) | Heap leach | 7 | 2.11 | 1 | 1,704 | 3.03 | 166 | 1,711 | 3.03 | 166 | 214 | 2.44 | 17 | | | CIL | - | - | - | 12,475 | 2.11 | 848 | 12,475 | 2.11 | 848 | 2,549 | 1.85 | 152 | | | FLOT/POX/CIL | - | - | - | 35,900 | 2.72 | 3,142 | 35,900 | 2.72 | 3,142 | 2,813 | 2.75 | 249 | | | Total - AUEQ | 7 | 2.11 | 1 | 50,079 | 2.58 | 4,156 | 50,086 | 2.58 | 4,156 | 5,576 | 2.33 | 418 | | | | kt | g/t | koz/Mlb | kt | g/t or % | koz/Mlb | kt | g/t or % | koz/Mlb | kt | g/t or % | koz/Mlb | | TOTALS | Au | 7 | 1.95 | 0 | 50,079 | 2.45 | 3,949 | 50,086 | 2.45 | 3,950 | 5,576 | 2.21 | 396 | | | Ag | 31.5 | 7 | 10.6 | 17,048 | 10.6 | 17,055 | 10.9 | 1,949 | | | | | | | Zn | - | - | 0.25 | 278 | 0.25 | 278 | 0.21 | 26 | | | | | | | AuEq | 2.11 | 1 | 2.58 | 4,156 | 2.58 | 4,156 | 2.33 | 418 | | | | |

| Mineral Resources Notes: | | | 1. | CIM (2014) definitions were followed for Mineral Resources. The mineral resource estimate for Camino Rojo has an effective date of March 31, 2025. | | 2. | The Qualified Person responsible for the mineral resource estimate is Marie-Christine Gosselin, P.Geo ., Senior Resource Geologist of SLR Consulting (Canada) Ltd. | | 3. | Mineral resources are estimated using a long-term price of US$2,300 /oz gold, US$1.25 /lb zinc and US$29 /oz silver and the following smelter terms: for oxide 99.9% payable Au and 98% payable Ag, and for sulphide 95% payable Au, 90% payable Ag and 95% payable Zn. Offsite costs (refining, transport and insurance) of US$145 /wmt transportation and US$230 /dmt treatment; a 2.5% NSR royalty. | | 4. | Metallurgical recoveries vary according to geometallurgical domains from heap leach, CIL, and flotation CIL with POX and are either constant or formula based. Heap leach recoveries range from 40% to 70% for gold and from 11% to 34% for silver. For CIL and CIL with POX, gold and silver recoveries are calculated using grade dependent formulae. The underground CIL mean recovery is 92% for gold and 36% for silver. The underground CIL with POX mean recovery is 85% for gold and 41% for silver. Zinc recovery by flotation is 80%. | | 5. | Mineral Resources are estimated in underground resource panels using NSR cut-off grades of 59.02 US$/t for leach material, 68.73 US$/t for CIL material, and 76.23 US$/t for CIL w/POX material. Underground resource panels have a minimum width of 2m. | | 6. | The NSR for heap leach material is calculated with the following formula: NSR ($/t) = US$71.98 x Au recovery x Au grade + US$0.84 x Ag recovery x Ag grade (g/t). The NSR for CIL material is calculated with the following formula: NSR ($/t) = US$68.34 x Au recovery x Au grade (g/t) + US$0.73 x Ag recovery x Ag grade (g/t). The NSR for CIL w/POX material is calculated with the following formula: NSR ($/t) = US$68.34 x Au recovery x Au grade (g/t) + US$0.73 x Ag recovery x Ag grade (g/T) + US$0.00146 x Zn recovery x Zn grade (ppm). | | 7. | The gold equivalent (AuEq) for heap leach material is calculated with the following formula: Au grade (g/t) + (US$0.84 x Ag recovery x Ag grade (g/t)) /(US$71.98 x Au recovery). The AuEq for CIL material is calculated with the following formula: Au grade (g/t) + (US$0.73 x Ag recovery x Ag grade (g/t)) / (US$68.34 x Au recovery). The AuEq for CIL w/POX material is calculated with the following formula: Au grade (g/t) + (US$0.73 x Ag recovery x Ag grade (g/t)) / (US$68.34 x Au recovery) + (US$0.00146 x Zn recovery x Zn grade (ppm)) / (US$68.34 x Au recovery). | | 8. | Numbers may not add due to rounding. |

The Mineral Resource estimate includes Inferred Mineral Resources that are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

The following factors, among others, could affect the mineral resource estimate: commodity price and exchange rate assumptions, pit slope angles, assumptions used in generating the resource pit shell and underground resource panels, including metal recoveries, and mining and process cost assumptions.

Evolution of Camino Rojo Deposit:

Orla's north-to-south drilling programs from Q4-2020 to Q4-2024, together with historical drilling data, have been instrumental in enhancing the geological model. This work has significantly refined the understanding of the distribution and geometry of sulphide-bearing veins hosted within the Caracol Formation, which includes both the oxide and much of the sulphide mineralization (except for Zone 22).

Zone 22 had previously been partially intersected by historical drilling but lacked a supporting geological model to define its geometry or potential extension into the deeper carbonate-rich formations below the Caracol Formation. Orla's updated model enabled strategic drilling along a section drilled in 2023, targeting the down-plunge extension of the deposit. This drilling confirmed the model and supported follow-up drilling in 2024 to define and expand Zone 22.

Initially, the development path for the sulphide component of the Camino Rojo deposit was conceived as a large open pit operation. However, initial estimates by previous operators, and later by Orla, indicated that such a scenario would require significant waste stripping, extension of the projected open pit onto a third-party property that Orla does not own, and construction of a large processing facility. The underground development scenario offers a more focused, high-value approach. This strategy involves selectively targeting higher-grade and more metallurgically favourable portions of the deposit (those amenable to direct cyanide leaching) as an initial phase of mining. Subsequent phases would address mineralization requiring pre-treatment, such as pressure oxidation, prior to cyanidation. Additionally, the underground development could operate in parallel with the ongoing oxide open pit. The upcoming PEA is expected to evaluate the underground mineral resource as an expansion of the current operation which would allow Orla to retain full project value.

Development Pathway / Next Steps:

Current and Planned Future Exploration

In 2025, Orla is advancing a 15,000-metre drilling program aimed at upgrading and expanding the upper part of the Zone 22 resource, with 11,000 metres drilled to date. Visual drill intercepts continue to support the geological model and continuity of mineralization. This program is expected to be completed in the third quarter and is anticipated to extend and infill the down-plunge extension.

The next phase of exploration to support the possible development of the underground deposit (including Zone 22) includes the planning of an underground exploration drift (decline). An exploration drift would provide access for tighter-spaced underground drilling aimed at further resource definition and, in parallel with technical studies, support advancement toward Mineral Reserve estimation. Permitting and early development planning is ongoing, and construction of an exploration drift could commence as early as 2026.

In November 2024 , Orla submitted permit applications to Mexico's environmental and natural resources agency, SEMARNAT ( Mexico's Secretaría del Medio Ambiente y Recursos Naturales). These included amendments to the existing oxide open pit permit. Orla also requested permits for an underground portal and exploration drift to support a potential transition to underground mining at Camino Rojo. The underground portal would be established within the current final open pit.

Preliminary Economic Study

Engineering and metallurgical studies are currently underway and will intensify and expand, with the objective of delivering a Preliminary Economic Assessment (PEA) in 2026. This PEA is expected to provide a conceptual operational plan and demonstrate the potential value for the development of the underground operations at Camino Rojo.

Development Planning

While establishing the plan for an exploration decline, Orla will continue metallurgical testing and other technical work with the goal of quickly progressing into feasibility level studies and final permitting for the complete underground operations and the required surface facilities. The aim of the conceptual development plan allows for a seamless transition from open pit mining to underground operations at Camino Rojo.

Camino Rojo Deposit:

The Camino Rojo deposit comprises three continuous zones with distinct characteristics:

1. The Camino Rojo Oxide Deposit ("Camino Rojo Oxides"), 2. The Camino Rojo Sulphide Deposit ("Camino Rojo Sulphides", or "Sulphides"); and 3. Zone 22 (Figure 2a), an extension of the Sulphides.

Longitudinal Sections of the Camino Rojo deposit show the three mineralized zones and new resource block model (Figure 2a), as well as the distribution of gold grades (Figure 2b ).

The Camino Rojo Oxide zone extends from surface to a vertical depth of approximately 250 metres, covering 900 metres along strike and up to 400 metres in width.

The Camino Rojo Sulphide zone lies between 250 and 700 metres below surface (or up to one kilometre down plunge), extending approximately one kilometre along strike and up to 400 metres in width.

Zone 22 mineralization has been defined over 500 metres along strike, extending from 700 to 1,300 metres vertical depth below surface (or over 1.2 kilometres down plunge), within a width of 200 to 400 metres, predominantly concentrated along and extending from the dike structure. Figure 3 is a representative cross-section of Zone 22, showing gold mineralization within the different host rock formations.

Camino Rojo Oxide and Sulphides Geological Controls

The Camino Rojo Oxide and Sulphides zones are predominantly hosted within flat-lying to gently dipping graded sandstone to mudstone beds of the Caracol Formation (Fm), as well as within a steeply northwest-dipping diorite dike. The dioritic dike shows true thicknesses ranging from tens of centimetres to tens of metres, reaching up to 24 metres, with an average of approximately seven metres. Both the Caracol Formation and diorite dike have undergone potassic alteration, predominantly characterized by pervasive adularia alteration.

Gold mineralization in the Camino Rojo Sulphides zone is controlled by mutually crosscutting, centimetre-scale Au-Ag-Zn±Pb-bearing veins that dip moderately to steeply northwest and shallowly southwest. These vein sets define gold-bearing mineralized domains that are up to tens of metres thick. In the northeastern portion of the deposit, gold-bearing veins crosscut the dioritic dike. Down plunge, to the southwest and toward the base of the Caracol Formation, these veins continue to crosscut the dike and locally exploit the intrusive contact.

Oxidation is pervasive within the upper 150-200 metres of the deposit, transitioning to sulphide mineralization between 200 and 250 metres below surface. However, oxidation extends as deep as 650 metres along structures.

Zone 22: Initial drilling to resource in two years; open for upgrade and expansion

Ongoing exploration at Camino Rojo continues to expand the deposit's footprint and refine geological understanding, defining additional mineralization beyond the currently outlined mineral resource.

Drilling by Orla, guided by the updated geological model, has confirmed that mineralization extends into lower stratigraphic units, showing styles distinct from those hosted in the overlying Caracol Formation.

Zone 22, which represents the vertical and down-plunge continuation of the Camino Rojo Sulphides, has been drilled to nearly one kilometre below the Caracol Formation, extending into the limestone-rich Indidura, Cuesta del Cura, La Peña, and Cupido formations. The zone remains open at depth and down-plunge. To date, mineralization has been identified across all rock formations exposed or drilled at Camino Rojo.

The Indidura Formation marks the transition to semi-massive to massive sulphide (Au-Ag-Zn) replacement along bedding (manto) and dioritic dike margins. Individual manto intersections are typically decimetre-scale and are traceable for up to 300 metres along strike and up to 150 metres into the hanging wall and footwall of the dike. Calc-silicate skarn alteration and associated Au-Ag-Cu mineralization are constrained to a halo along the hanging wall and footwall of the dike, extending tens of metres from the dike.

Metallurgical Test work and Recovery Model:

Metallurgical testing of the Camino Rojo deposit has been conducted through multiple programs by previous operators. Since 2021, Orla has focused on defining optimal recovery processes and maximizing metal recoveries from higher-grade zones suitable for underground mining. This has included bottle roll, flotation, and oxidation test work on both master composite and variability samples from the Camino Rojo Sulphides. All Orla metallurgical studies for the Camino Rojo Sulphides have been completed by Blue Coast Research of Parksville, Canada under the guidance of Andrew Kelly , P.Eng.

Based on the metallurgical testing results to date, three conceptual mineral resource process streams have been identified that inform the recovery model assumptions of the Camino Rojo underground mineral resource (Measured, Indicated, Inferred):

1. Heap leach (existing infrastructure), 3% of the tonnage of the underground Mineral Resource, with gold recovery ranging from 40% to 70% 2. Carbon -in-leach (CIL), 27% of the tonnage of the underground Mineral Resource, with a mean gold recovery of 92%, and a mean silver recovery of 36% 3. CIL with Pressure Oxidation (POX): 70% of the tonnage of the underground Mineral Resource, with a mean gold recovery of 85%, and a mean silver recovery of 41%. A separate zinc concentrate can be produced prior to POX with zinc recovery of 80% expected from the highest-grade zones.