Announcement PDF ASX ANNOUNCEMENT 18 SEPTEMBER 2026 ASX: TSO OTCQX: TSORF FSE: 5D7 31 Cliff Street, Fremantle WA 6160 | +61 8 6383 7883 | info@tesorogold.com.au | tesorogold.com.au MAIDEN 1.28MOZ ORE RESERVE AT TERNERA SINGLE-PIT ORE RESERVE PROVIDES A 13+ YEAR DEVELOPMENT BASE Tesoro Gold Limited (Tesoro, or the Company) (ASX: TSO, OTCQX: TSORF, FSE: 5D7) is pleased to report a maiden Ore Reserve comprising 1.28Moz of contained gold for the Ternera Gold Deposit (Ternera), part of the El Zorro Gold Project in Chile (El Zorro, or the Project). The Ore Reserve is contained entirely within a single open pit and represents approximately 87% of the 1.47Moz of gold contained within the Measured and Indicated components of the August 2026 Mineral Resource Estimate (MRE), demonstrating a high conversion of the Ternera MRE base into Ore Reserves (see Table 1 and 3 and Figure 4). The Ore Reserve supports a substantial, long-life development at the planned 3.0Mtpa process rate. The Reserve pit was designed based on a US$3,000/oz gold price optimal pit shell. It is underpinned by Pre-Feasibility (PFS) mine designs and schedules and the application of Modifying Factors informed by work completed across mining, geotechnical, metallurgy, processing, infrastructure, environmental and cost workstreams. The ultimate Reserve pit is based on a shell selected from pit optimisation using a US$3,000/oz gold price. This work provides a robust foundation for the Definitive Feasibility Study (DFS), through which Tesoro will evaluate further opportunities to optimise the Project as the technical and development workstreams are refined. HIGHLIGHTS • Maiden Ore Reserve of 42.8Mt at 0.93g/t Au for 1.28Moz of contained gold, entirely within a single open pit at Ternera. • High Mineral Resource conversion, with the Ore Reserve representing approximately 87% of the 1.47Moz of Measured and Indicated Resource ounces. • Ore Reserve supports a project production life of more than 13 years at an average grade of 1.16 g/t Au for first 10 years of production. • Mining via a conventional single open pit mining and a 3.0Mtpa crushing, grinding, gravity and CIP processing flowsheet. • The ultimate Reserve pit is based on a pit shell selected from optimisation using a US$3,000/oz gold price, approximately 30% below the spot gold price at the time of optimisation. • The Ore Reserve supporting PFS-level work provides a robust foundation for the DFS, targeted for completion during CY2026. The DFS will refine the project design, economics and assumptions and evaluate opportunities to further optimise the Project. • Ternera benefits from being located in a low-altitude coastal setting, 13km inland from the Pacific Ocean and approximately 57km by road from the port of Caldera, with established regional road, power and water infrastructure. • Further growth potential is being tested through ongoing drilling of extensions to Ternera and a broader portfolio of priority discovery targets across the El Zorro Gold District. ASX Announcement 18 September 2026 Tesoro Gold 2 Table 1: Ternera Deposit Ore Reserves Summary as at 16 September 20261 PROVED PROBABLE TOTAL Deposit Type Cut-off Tonnes Au Gold Tonnes Au Gold Tonnes Au Gold g/t Au Mt g/t koz Mt g/t koz Mt g/t koz Ternera Open Pit 0.30 2.8 1.05 93 40.1 0.92 1,190 42.8 0.93 1,283 Tesoro Managing Director, Zeff Reeves, commented: “The Ternera Gold Deposit represents a rare, single open pit development opportunity in a world- class mining friendly country. Establishing this initial 1.28Moz Ore Reserve is a significant step for our El Zorro Gold Project. The Reserve is supported by more than 160km of diamond drilling completed at Ternera since its initial discovery and the recent significant upgrade to geological confidence of the Mineral Resource base. Importantly, this Reserve contains approximately 87% of the gold currently classified within the Measured and Indicated Mineral Resource. That is a strong conversion outcome and is reflective of the consistency of mineralisation at Ternera. We now have a substantial Ore Reserve contained entirely within a single open pit which supports more than 13 years of production at the planned 3.0Mtpa processing rate. This gives us a strong development base at Ternera, which still has significant upside to be unlocked from further drilling. We will continue advancing the technical and development workstreams for El Zorro in parallel with drilling as multiple rigs pursue extensions to the existing Ternera Resource and high-priority discovery targets across the broader El Zorro Gold District." Cautionary Statement The PFS (or the Study) referred to in this announcement has been undertaken by Tesoro in conjunction with various independent consultants, to determine the viability of a standalone development, including open pit mining and processing at the El Zorro Gold Project (comprising of the Ternera Gold Deposit) in Chile. The total Life of Mine Production Target (and forecast financial information derived from the Production Target) referred to in this announcement is underpinned entirely by Proved and Probable Ore Reserves. The Company confirms that the Ore Reserves estimates and Mineral Resources estimates have been prepared by Competent Persons in accordance with the requirements of the JORC Code. This announcement has been prepared in compliance with the JORC Code 2012 Edition (JORC 2012) and the ASX Listing Rules. All material assumptions on which Life of Mine Production Target and the forecast financial information is based have been provided in this announcement and are also outlined in the attached JORC 2012 Table 1 disclosures. While the Company considers all the material assumptions to be based on reasonable grounds, there is no certainty that they will prove to be correct or that the production target or estimated outcomes indicated by the PFS (such as the financial forecasts) will be achieved. The production target and estimated outcomes indicated by the PFS (such as the financial forecasts) are also subject to various risk factors. See the Cautionary Statements and Forward Looking Statements disclaimer at the end of this announcement. Given the uncertainties involved and detailed in this announcement, investors should not make any investment decision based solely on the results of the PFS. 1 Ore Reserves reported in accordance with the JORC Code (2012 Edition) and are a subset of Mineral Resources. Ternera Ore Reserves are estimated based on pit designs guided by pit shell selected from optimisations using a gold price of US$3,000/oz and using a cut-off grade over 0.3g/t Au. Figures have been rounded to the nearest 100,000 tonnes and 1,000 ounces and may not sum perfectly. ASX Announcement 18 September 2026 Tesoro Gold 3 Figure 1: Ternera Deposit Ore Reserve Final Pit – Plan View ASX Announcement 18 September 2026 Tesoro Gold 4 Figure 2: Ternera Deposit Ore Reserve Pit Section 7036200N (looking north) Figure 3: Ternera Deposit Open Ore Reserve Pit Section 341800E (looking west) ASX Announcement 18 September 2026 Tesoro Gold 5 TERNERA MAIDEN ORE RESERVE The maiden Ternera Ore Reserve totals 42.8Mt at 0.93g/t Au for 1.28Moz of contained gold and is contained within a single open pit, reported above an economic cut-off grade of 0.3g/t Au. The Ore Reserve has been calculated using the August 2026 Ternera Mineral Resource Estimate and includes only Measured and Indicated material. No Inferred Mineral Resources have been included in the Ore Reserve. The economic cut-off grade for the Ore Reserve has been calculated based on PFS modifying factors for the project. The cut-off grade is estimated by the following formula: Cut-off Grade = ((mining cost + processing operating cost + G&A cost) x (1 + dilution)) (recovery x (metal price - selling cost) x payability) The economic cut-off grade for the Ternera Ore Reserve based on PFS modifying factors over a range of gold priced is shown in the table below. Table 2: Ternera Ore Reserve Economic Cut-off scenarios GOLD PRICE US�3,000/OZ US�3,250/OZ US�3,500/OZ US�3,750/OZ US�4,000/OZ US�4,250/OZ Estimated Cut-off Grade (g/t Au) 0.30g/t 0.28g/t 0.26g/t 0.24g/t 0.23g/t 0.22g/t The El Zorro Ore Reserves are stated as the economically mineable part of the Measured and Indicated portion of the August 2026 Ternera Mineral Resource contained within the Reserve pit design above the cut-off grade for the selected gold price. Importantly, the Ore Reserve contained in the US$3,000/oz pit design represents approximately 87% of the 1.47Moz of gold contained within the Measured and Indicated Mineral Resource, demonstrating a high level of conversion of the Ternera Resource base into mineable Ore Reserves. The mine schedule, based purely on the Ore Reserve, supports a project production life of more than 13 years at the planned 3.0Mtpa processing rate, with a life-of-mine waste-to-ore stripping ratio of 6.3:1. The supporting modifying factors have been informed by PFS-level studies undertaken by Tesoro and specialist Australian and Chilean consultants. Table 3: Ternera Deposit August 2026 Mineral Resource Estimate Summary2 MEASURED INDICATED INFERRED TOTAL Cut-off Tonnes Au Gold Tonnes Au Gold Tonnes Au Gold Tonnes Au Gold g/t Au Mt g/t koz Mt g/t Koz Mt g/t koz Mt g/t Koz 0.30 2.4 1.24 95 37.9 1.13 1,371 11.3 0.98 356 51.6 1.10 1,822 2 Open Pit Mineral Resources were estimated using a gold price of US$3,500/ounce and estimated using a cut-off grade of 0.3g/t Au. Figures have been rounded to the nearest 100,000 tonnes and 1,000 ounces and may not sum perfectly. ASX Announcement 18 September 2026 Tesoro Gold 6 Table 4: Ternera Deposit Ore Reserves Summary as at 16 September 20263 PROVED PROBABLE TOTAL Deposit Type Cut-off Tonnes Au Gold Tonnes Au Gold Tonnes Au Gold g/t Au Mt g/t koz Mt g/t koz Mt g/t Koz Ternera Open Pit 0.30 2.8 1.05 93 40.1 0.92 1,190 42.8 0.93 1,283 A summary is provided below of information material to understanding the reported Ore Reserve estimate. This announcement has been compiled in compliance with the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code – 2012 Edition) (JORC Code) and the ASX Listing Rules (including ASX Listing Rule 5.9). Classification – Ore Reserve Estimate The main basis of classification of Ore Reserves is the underlying Mineral Resource classification. All Proved Reserves are derived from Measured Mineral Resources, and all Probable Ore Reserves derive from Indicated Mineral Resources in accordance with JORC (2012). The results of the Ore Reserve estimate reflect the Competent Person’s view of the deposit. No Inferred Mineral Resources are included in the Ore Reserves. Figure 4: Ternera Ore Reserve’s High Conversion from Measured and Indicated Resources Establishes a 13+ Year Single-pit Development Base 3 Ore Reserves reported in accordance with the JORC Code (2012 Edition) and are a subset of Mineral Resources. Ternera Ore Reserves are estimated based on pit designs completed on selected pit shells from pit optimisations using a gold price of US$3,000/oz and using a cut-off grade over 0.3g/t Au. Figures have been rounded to the nearest 100,000 tonnes and 1,000 ounces and may not sum perfectly. ASX Announcement 18 September 2026 Tesoro Gold 7 EL ZORRO GOLD PROJECT Location and Infrastructure The El Zorro Gold Project covers approximately 570km2 within Chile’s mining-friendly Atacama Region, approximately 130km north of Copiapó within the Coastal Cordillera. Ternera is located 13km inland from the Pacific Ocean and 57km by road from the port of Caldera. The Project benefits from its low-altitude coastal setting and proximity to established regional infrastructure, including sealed road access together with grid power and water supply options. Chile is recognised as one of the world’s premier mining jurisdictions, with a well-established regulatory framework and strong Government and investment support for responsible mine development. Tesoro's 95%-owned Chilean subsidiary, Tesoro Mining Chile SpA, currently holds a 94.5% interest in the El Zorro Gold Project within a fully diluting joint venture structure. Figure 5: El Zorro Gold Project – Regional Location Map (red outline showing El Zorro Concessions, with the Ternera Gold Deposit located at blue circle) ASX Announcement 18 September 2026 Tesoro Gold 8 SUPPORTING TECHNICAL INFORMATION Ore Reserve and Mineral Resource Basis The updated MRE announced in August 2026 is based on 153,180m of diamond drilling from 474 holes, uses a 0.30g/t Au cut-off, with the open pit portion constrained within a US$3,500/oz open pit shell. Table 5: Ternera Deposit August 2026 Mineral Resource Estimate Summary4 MEASURED INDICATED INFERRED TOTAL Cut-off Tonnes Au Gold Tonnes Au Gold Tonnes Au Gold Tonnes Au Gold g/t Au Mt g/t koz Mt g/t Koz Mt g/t koz Mt g/t Koz 0.30 2.4 1.24 95 37.9 1.13 1,371 11.3 0.98 356 51.6 1.10 1,822 The global August 2026 MRE unconstrained by an optimal pit shell is 1.93Moz at 1.07g/t Au. The update material increased confidence in the Ternera MRE, adding 252koz, or 44% to the Indicated classification, and establishing the first 95koz Measured Resource at the Deposit. Measured and Indicated Resources contain 1.47Moz of gold and represent 78% of the open pit constrained Mineral Resource. The increased level of resource confidence provided the basis for estimation of the maiden Ore Reserve, derived from Measured and Indicated Resources. Ternera Deposit Geology The Project is located within the Chile’s Coastal Cordillera. Gold mineralisation is predominately hosted within numerous intermediate intrusions and associated quartz and sulphide veins, veinlets, and alteration within faulted and strongly altered tonalitic intrusions known as the El Zorro Tonalite (or EZT). The EZT intrusions have intruded Permian aged basement sedimentary sequences. Gold mineralisation at Ternera has been classified as an Intrusive Related Gold System (IRGS), with Tesoro having successfully identified multiple additional gold targets across the wider El Zorro District displaying similar geology and styles of gold mineralisation. Mineralisation is interpreted to be associated with regional scale north-south striking fault zones and related local north-west striking strike-slip faults. Gold occurs within discontinuous shoots controlled by a combination of the intersection of the structures with the preferred host rock tonalite, and locally developed intersections of fracture populations that developed during strike-slip deformation. Basis of Cut-Off Grade Applied The Resource has been reported at a 0.3g/t Au cut-off based on the costs and recoveries used in generating the optimal pit shell for a US$ 3,000 per ounce gold price. Estimation Methodology Estimation of gold grade in the tonalite domains is carried out with an Ordinary Kriging methodology using Micromine 2026.5 software. The initial estimation generates a preliminary block model. This model is sub-divided into mineralised and unmineralised domains, using a cut-off of 0.2g/t Au. 4 Open Pit Mineral Resources were estimated using a gold price of US$3,500/ounce and estimated using a cut-off grade of 0.3g/t Au. Figures have been rounded to the nearest 100,000 tonnes and 1,000 ounces and may not sum perfectly. ASX Announcement 18 September 2026 Tesoro Gold 9 A second pass of Kriging uses these sub-domains to produce mineralised and unmineralised block estimates of gold grade. A third estimation is then carried out within the mineralised tonalite domains using more restricted search and sample number criteria with a strike of 345⁰ and a vertical dip. Estimation of gold grade within the metasediments also carried by Ordinary Kriging with a strike of 345⁰ and a vertical dip. A dynamic search technique is used in the estimation of the tonalites, which allows the search strategy to follow the local variations in dip and strike of the mineralisation. In the fault domains between the tonalite intrusions a vertical, north-south search was used. The estimation process was validated by comparing global block grades with the average composite grades, visual checks comparing block grades with raw assay data and swathe plots. All methods showed good correlation between drill hole data and block model. Mining Method, Design and Assumptions Ternera is planned to be developed as a conventional single open pit mining operation, with ore processed through the planned 3.0Mtpa processing facility. Ore Reserves were estimated by generating a series of nested, optimised pit shells using open pit optimisation software, with selected shells used as the basis for detailed pit designs. Mine designs and extraction sequences have been completed that reflect the geometry of the Deposit, incorporate estimated dilution and ore loss, achieve acceptable rates of mining, utilise planned process plant capacity and optimise free cash generation in a safe manner. The open pit has been scheduled based on achievable mining productivity and rates and consistent material movement assumptions, utilising mining equipment commonly used in this style and scale open pit mining operations. Ore mining will be selective utilising the appropriate scale mining fleet and flitch heights to suit the geometry of the deposit. This approach has been incorporated in the mining cost estimates. Figure 6: Ternera PFS Mining Schedule Mining costs have been developed based on pit and mining infrastructure designs using an alliance- style framework between Tesoro and STRACON Chile SpA. As announced to the ASX on 1 July 2026, Tesoro and STRACON have signed a non-binding Letter of Intent (LOI) to establish an alliance-style framework. Under the LOI it is proposed that Tesoro and STRACON would work within ASX Announcement 18 September 2026 Tesoro Gold 10 an integrated operating framework, with individual phases proceeding under separate Notices to Proceed at Tesoro's discretion. Mining Dilution and Ore Loss Mining dilution, mining recovery and ore loss have been incorporated in the Ore Reserve estimate using detailed modifying factors designed to reflect practical open pit mining conditions. The Ternera Mineral Resource block model was first regularised to a 2.5m x 2.5m x 2.5m selective mining unit (SMU) to better represent the scale at which the Deposit is expected to be mined. This process very clearly demonstrates the consistency of the Ternera mineralised inventory, with regularisation resulting in an approximately 12% increase in tonnes above the 0.3g/t Au cut-off and approximately 11% reduction in grade, for a 3% reduction in contained ounces. The regularised model was then subject to an assessment for isolated or non-mineable blocks, which were excluded from the Ore Reserve, resulting in a further 3% reduction in ore tonnes. Additional mining dilution was then estimated on the SMU block model (excluding isolated ore blocks) using a geometric skin-depth methodology, with a 0.5m dilution skin applied to mineralised zones. Adjacent Measured and Indicated material below the economic cut-off retains its estimated grade, while adjacent Inferred material is conservatively assigned a grade of 0g/t Au for Ore Reserve purposes. Estimated dilution from this methodology results in a further increase of 11% on tonnes and a reduction of 9% of grade above the 0.3g/t Au cut-off in addition to the dilution impact associated with SMU regularisation. Total dilution of this process from MRE to ORE results in an additional 23% on tonnes, a reduction of 20% on grade and a 2% reduction in contained ounces above the 0.3g/t Au cut-off. These outcomes demonstrate that the contained gold inventory remains highly consistent through successive practical mining adjustments, providing a high level of confidence in the conversion of the Mineral Resource in a mineable Ore Reserve. Table 6: Ternera Ore Reserve Conversion Summary (Measured and Indicated Only) CONVERSION STEP TONNES GRADE CONTAINED AU TONNES GRADE CONTAINED AU Mt g/t koz % % % M&I Mineral Resource within Reserve Pit 34.7 1.16 1,300 100% 100% 100% SMU regularisation (planned dilution and ore loss) 39.0 1.03 1,258 112% 89% 97% Isolated-block model (ore loss) 37.8 1.04 1,270 109% 90% 98% 0.5m Skin dilution (mining dilution) 42.8 0.93 1,280 123% 80% 98% Ore Reserve 42.8 0.93 1,280 123% 80% 98% ASX Announcement 18 September 2026 Tesoro Gold 11 Figure 7: Ternera Ore Reserve Cumulative Tonnage Grade Curve (LHS: Cumulative Tonnes (Mt), RHS: Au Grade (g/t)). Figure 8: Ternera Ore Reserve Tonnage Grade Curve (LHS: Discreet Tonnes (Mt), RHS: Au Grade (g/t)). ASX Announcement 18 September 2026 Tesoro Gold 12 Geotechnical Modelling Pit wall angles used in the Ore Reserve study were based on a geotechnical assessment completed by Peter O’Bryan & Associates. The assessment included a review and inspection of available exploration core, geological and structural interpretations, laboratory rock-property testing, rock-mass classification, kinematic stability assessment, limit-equilibrium analysis and empirical assessment of potential slope performance. The resulting preliminary base-case pit wall design parameters have been incorporated into the open pit design. Table 7: Ternera Geotechnical Study Summary WALL DESIGN PARAMETER SCREE/ GRAVELS NOMINALLY 0 MBS TO 5 MBS WEATHERED AND FRESH ROCK BELOW 5 MBS ALTERNATE DESIGN PARAMETERS 1 FOR WEATHERED ROCKS 5 MBS TO TOFR Batter Height 5.0m 10.0m 10.0m Batter Face Angle 40° 85° 60° Berm Width 4.0m 10.0m 5.0m IRA 26.7° 42.6° 42.9° Bench Stack Berm Width (at ≤ 100 m vertical intervals) N/A 15 m 15 m ASX Announcement 18 September 2026 Tesoro Gold 13 Infrastructure Planned mine infrastructure includes waste rock dumps, ROM pads, surface-water management facilities, equipment workshops, explosives magazines, supply facilities and administration facilities. Figure 9: Proposed El Zorro Gold Project Site Layout. ASX Announcement 18 September 2026 Tesoro Gold 14 Figure 10: Proposed El Zorro Gold Project Water and Power Infrastructure Solution. Metallurgy and Processing Three phases of metallurgical test work have demonstrated strong and consistent gold recoveries from Ternera mineralisation using conventional gravity and cyanide-leach processing. All metallurgical test work was completed at the ALS Laboratory in Perth, Western Australia, with the final two phases undertaken under the supervision of GR Engineering Services (GRES). These results support a simple, conventional 3.0Mtpa crushing, grinding, gravity and (carbon-in- pulp) CIP process flowsheet. The selected processing flowsheet comprises: • multistage crushing; • ball milling; • gravity gold recovery; • cyanide leaching; • carbon-in-pulp gold recovery; • conventional elution and electrowinning; and • smelting to produce gold doré. ASX Announcement 18 September 2026 Tesoro Gold 15 A single-toggle jaw crusher powered by a 200kW motor and secondary and tertiary cone crushers fitted with 670 kW motors, followed by a single 9.2 MW ball mill grinding circuit has been designed for a nominal 3.0Mtpa throughput, operating at a design feed rate of 375 t/h and producing a P80 grind size of 125 µm. Gravity gold will be recovered via two centrifugal gravity concentrators followed by an intensive leach reactor. The leach circuit comprises four leach tanks providing 16 hours residence time followed by six CIP tanks providing a further 6 hours, for a total leach and adsorption residence time of 22 hours. Gold is recovered by standard elution and electrowinning techniques prior to smelting. Filtered tailings will be transferred to a dry-stack tailing storage facility where they will be placed in controlled layers and compacted. The design incorporates a 15m-wide rockfill upstream shell to mitigate erosion, with the downstream toe positioned on competent rock to reduce seismic risk. Figure 11: Simplified El Zorro Gold Project Process Flowsheet Metallurgical Recovery The test work programme assessed representative lithologies and grade ranges expected within the Ternera mine plan and demonstrated a highly consistent metallurgical response across the Deposit, providing the basis for the recovery assumptions and processing flowsheet adopted for the Ore Reserve. Testing also assessed the use of waste brine water from the Caldera desalination facility as process water, with brine water successfully used throughout the relevant gravity and leach test work. Physical property and comminution parameter testing was completed on the four representative composites and included SMC testing together with the calculation of Bond Impact Crushing Work (CWi), Bond Abrasion (Ai), Bond Rod Work (RWi) and Bond Ball Mill Work (BWi) indices. Outcomes indicate that Ternera ore is hard to very hard, with relatively consistent physical characteristics across tested samples. ASX Announcement 18 September 2026 Tesoro Gold 16 Table 8: Ternera Gold Deposit Comminution Test Work Results Summary COMPOSITE ID CWI (KWH/T) JK SMC A*B BOND AI BOND RWI BOND BWI (KWH/T) Composite 1 6.2 24.9 0.1863 25.5 21.1 Composite 2 3.8 30.8 0.1356 22.8 19.9 Composite 3 4.3 22.0 0.2374 25.2 21.0 Composite 4 4.5 23.0 0.1576 24.0 19.8 Testing across a range of grind sizes returned overall gold extractions of between 92.4% and 97.4%. A grind size of 125 µm was selected for the process design. At this grind size, the four composites returned 48-hour gold extractions of approximately 95.1% to 96.0%. Leach kinetics were rapid, with the majority of gold extraction occurring within the first 8 to 12 hours. Based on the metallurgical test work results the process designed total gold recovery at the selected 125 μm grind size was 94.5% gold extraction, and was the basis used for Ore Reserve calculation. Key outcomes from metallurgical test work include: • consistent metallurgical performance across the tested composite and master samples; • approximately 95% or greater overall gravity/leach gold extraction at the selected 125 μm grind size; • positive gravity-recoverable gold response; • no deleterious elements or preg-robbing tendencies identified; and • Low cyanide consumption of less than 0.2 kg/t NaCN consumed from 0.6 kg/t added reagent; low variability in metallurgical response across the tested composites. The ore is siliceous and brittle and fractures readily during crushing. The high BWi values indicate that the ore is not amenable to autogenous or semi-autogenous grinding and supports the selected ball-milling flowsheet. Variability in results across composites is low, providing confidence to support advanced levels of technical studies. Table 9: Composite Sample Gravity/Leach Results at Various Grind Sizes GRAVITY/LEACH TEST WORK AND THE INFLUENCE OF GRIND Composite ID Leach Regrind P80 (μm) Au Extraction (%) at Various Increments (hours) % (Grav) 2 4 8 24 48 Composite 1 150 43.1 72.8 83.7 88.4 92.0 93.4 125 44.6 74.9 87.3 92.6 95.2 95.9 106 43.9 74.9 87.2 92.8 94.2 95.6 90 44.2 81.9 90.0 94.5 95.6 96.3 75 44.7 81.5 92.4 95.4 96.9 97.3 Composite 2 150 34.8 82.7 88.3 91.2 94.0 95.5 125 35.1 76.0 88.0 92.2 94.7 95.9 ASX Announcement 18 September 2026 Tesoro Gold 17 GRAVITY/LEACH TEST WORK AND THE INFLUENCE OF GRIND Composite ID Leach Regrind P80 (μm) Au Extraction (%) at Various Increments (hours) % (Grav) 2 4 8 24 48 106 34.8 82.8 89.7 93.9 96.1 96.7 90 35.0 83.8 90.4 94.3 96.2 97.1 75 35.0 80.7 91.6 94.9 97.4 97.4 Composite 3 150 52.1 77.3 85.4 90.5 93.3 94.2 125 48.0 71.3 81.6 89.5 93.5 96.0 106 44.6 60.1 71.0 79.8 89.8 96.6 90 52.2 73.5 86.6 94.0 96.5 97.4 75 52.4 82.1 90.4 95.5 97.4 97.4 Composite 4 150 34.8 73.4 83.1 89.4 91.4 92.4 125 35.8 78.9 85.6 92.0 94.1 95.1 106 33.9 74.7 87.2 93.3 96.3 96.3 90 33.3 72.4 85.8 90.8 92.7 93.7 75 35.0 74.9 87.9 94.2 95.2 96.2 Table 10: Master Composite Bulk Gravity/Leach Summary Result BULK GRAVITY/LEACH TEST WORK: MASTER COMPOSITE Test # Grind P80 (μm) Head Au (g/t) Leach Residue Au Consumption (kg/t) Assay Calc g/t NaCN Lime AT1735 125 2.08 1.90 0.10 0.46 2.65 Table 11: Master Composite Au Extraction at Various Increments BULK GRAVITY/LEACH TEST WORK: MASTER COMPOSITE Test # Grind P80 (μm) Au Extraction (%) at Various Increments (hours) 0 (Grav) 2 4 8 12 48 AT1735 125 26.7 68.3 79.6 89.5 93.2 95.0 ASX Announcement 18 September 2026 Tesoro Gold 18 Figure 12: Annual Mill Throughput and Head Grade (average 1.16 g/t Au for first 10 years of production). Figure 13: Annual Mill Head Grade and Gold Production Ounces (average 1.16 g/t Au for first 10 years of production). Regional and Project Infrastructure El Zorro is a Greenfield development with no existing project-specific infrastructure onsite. Grid power alternatives have been assessed, with the preferred concept involving connection to the Totoralillo substation owned by Compania Acero Pacifico approximately 21.6km in a straight line south-east of the Project. Tesoro has entered into a Memorandum of Understanding (MoU) with TECNOCAP S.A to investigate the transmission and supply of electricity to El Zorro using existing 220kV regional infrastructure. Tesoro has also entered a MOU to investigate the provision of wastewater (brine) to be pumped from the AguasCap Totoralillo desalination plant to the Project to be used as process water. The study also provides for construction and operation of an 800-man accommodation camp at the Project. ASX Announcement 18 September 2026 Tesoro Gold 19 Cost and Economic Assumptions Capital and operating cost estimates have been developed to a PFS-level by Tesoro in conjunction with specialist mining, engineering and infrastructure consultants and are currently stated at an accuracy of ± 25%. Capital costs have been estimated on a first-principals basis for the principal Project components. Pre-production capital is estimated to be US$276.5M, which includes the processing plant, some infrastructure, owners’ costs, mobilisation and establishment of the open pit mining