Oroco Resource Corp. (TSX-V: OCO) (OTCQB: ORRCF) is pleased to report the third set of assay results from its Phase 2 resource drilling program focused on the South Zone at its Santo Tomás copper project, Choix, Sinaloa, Mexico. Results are reported for drill holes S027 and S030 through S034.   The Company continues drilling with three rigs on site.

Highlights

Westernmost limit of inferred mineralization –central portion of the South Zone

• Holes S031 and S034 confirmed the local westward extension of mineralization beyond the current inferred block model limits in the central western portion of the South Zone.
• Hole S031 is a hole drilled westwards at -65 degrees from the same pad as S029 (previous release). The hole intersected near-surface mineralization and drilled out of inferred material, extending newly identified mineralization westwards. Mineralized outcrops to the west of the intercept suggest a wedge of mineralization extending up to 330m in that direction.
• Hole S033 was drilled at -50 degrees eastwards from a pad located 50m to the east of S034. Intersected mineralization included 26.48m @ 0.90% Cu / 1.18% CuEq* from a depth of 48.0m. Additional intercepts are included below.
• Hole S034 was collared 80m north of S031 and drilled westwards at -60 degrees. The hole displayed mineralization similar to that observed in S031 and, as with S031, intersected mineralization outside the inferred material. Surface mineralization to the west again supports a wedge of additional mineralization to the west.

South end of the South Zone– Holes containing Oxide and Transition mineralization

• Hole S027 is a vertical hole drilled from the same pad as S030 and S032. The mineralization observed in this hole, combined with results from S032 and S030 and surface expressions of copper oxides, essentially defines the southern limit of the South Zone.
• Holes S030 and S032 have locally defined a southern limit of mineralization in the South Zone.
• Hole S030, located on the same pad as S032, was drilled at -50 degrees towards 280^°. A 49m intercept of mixed oxide-sulphides was logged from 12m depth. Total copper assay over the interval returned 0.80% CuTot. Additional sulphide mineralization below this interval is included in Table 2.
• Hole S032 is located on the southernmost pad in the South Zone (S027 pad) and was drilled at -45 degrees towards 150^°. A mixed oxide-sulphide zone was observed from 0 to 49m depth. The total copper assay over the interval 36 to 49m returned 0.80% CuTot and 0.31% CuSol (total and soluble copper respectively). Sulphide mineralization below this interval is reported in Table 2.

“These Phase 2 results support the potential for additional resource outside of the 2024 Technical Report block model and continue to support the approach being taken at Santo Tomás,” said Charles Cryer, Oroco CEO. “Additional drilling to date in the southern half of the South Zone supports the potential for a higher-grade zone as first identified in Phase 1 drill hole S018. Drilling to the west also has the potential for additional tonnage beyond the inferred material classification limits.”

Soluble copper assays for Hole S027 were received and returned a 10.5 m mixed oxide-sulphide intercept from 13.5m depth with 0.53% CuTot and 0.17% CuSol. At this stage, there is no technical report that incorporates a plan for a copper leach recovery circuit. The Company has therefore elected not to report a copper equivalent grade for significant intervals of mixed oxide and sulphide mineralization.

Phase 2 Program Overview

IT IS IMPORTANT TO NOTE that Phase 2 is designed primarily to convert Inferred resources to the Indicated resource classification in the South Zone and to collect geotechnical, hydrogeological, and additional metallurgical data required for Pre-Feasibility Study mine planning. Resource drilling in the South Zone is almost complete. Rigs will thereafter be moved to “the Gap” in the pillar area between the North and South Zones. The PFS is targeted for release in Q2/Q3 2027.

Table 1: Phase 2 Drill Holes S027, S030, S031, S032, S033 and S034

Table 2: Significant Assay Results**

* CuEq (%) = [(Cu% × Cu recovery (variable) × Cu price) + (Mo% × Mo recovery (variable) × Mo price) + (Au g/t × Au recovery (variable) × Au price) + (Ag g/t × Ag recovery (variable) × Ag price)] ÷ (Cu price × Cu recovery (variable)). Metal prices are in US$/lb (Cu, Mo) and US$/oz (Au, Ag). See Table 3. Metal recoveries are grade-based by individual assay in the reported intervals and vary accordingly. In these intervals, Cu recovery ranges from 82-89%, Mo 50-60%, Au 30-85% and Ag 35-67%. Au and Ag recoveries are dependent on copper and sulphur grades.

Drill hole intervals reporting sulphide and non-sulphide copper (oxide) results are not reported with a copper equivalent.

**Significant Intervals comprise intervals ≥ 10m of ≥ 0.15% Cu, but may include assay intervals of ≤ 4m of ≥ 0.05% Cu. This continues the practice of significant interval reporting applied during Phase 1, including News Releases and the 2024 PEA.

⁺CuTot is the total contained copper % via ME-ICP62, four-acid digest.

⁺⁺CuSol is the soluble copper assay via Cu-AA05 using a sulphuric acid leach conducted on intervals exhibiting oxidation.

All intervals are downhole drill core lengths. True widths will be confirmed when Phase 2 results are incorporated into the updated geological and resource models. Where holes are drilled approximately perpendicular to the interpreted structural attitude of the mineralization, core intervals are expected to approximate true thickness.

Copper Equivalent Reporting

CuEq grades in this release are calculated using the variable metal recovery curves from Chapter 13 of the Company’s 2024 Technical Report (“Santo Tomás Copper Project, Sinaloa, Mexico — Technical Report on a Preliminary Economic Assessment” (the “PEA”), filed on SEDAR+ August 2024) and the metal price deck in Table 3, reflecting 12-month actual trailing average prices to April 30, 2026.   This price deck differs from that used in the PEA.

Copper equivalent grades in this release are not directly comparable to CuEq grades reported in the Company’s 2024 Indicated and Inferred Resource Summary Table or in earlier drill-result news releases prior to 2024, which used different metal price assumptions and CuEq methodologies. The Company has recalculated the significant-intercept database for the full drill-hole dataset using the updated CuEq calculation: the historical drilling results and the results for holes S022 to S034 have been updated in the VRIFY drill-hole viewer and are available at VRIFY and via the Company’s website. Intervals that include soluble copper assays do not have CuEq values calculated.

Table 3: Metal Prices Used for Phase 2 CuEq Calculations

Quality Assurance / Quality Control

Historical drilling data used in the resource estimate and design of the current exploration program were subject to the data verification procedures described in the Company’s current Technical Report. Drill collar locations are verified by differential GPS with checks against LiDAR data. Geological logging, core sampling, sample preparation, analysis, and chain of custody are governed by QA/QC protocols that include the insertion of certified reference standards, blanks, and duplicates. Samples are submitted to ALS Chemex (Hermosillo, Mexico) for sample preparation; pulps are sent to ALS Canada Ltd. (Vancouver) for analysis. Total copper, molybdenum, and silver are determined by ALS method ME-ICP61 (four-acid ICP-AES); over-limit results use ore-grade assay method Cu-OG62, and non-sulphide copper is determined by method Cu-AA05. Gold is determined by ALS method Au-AA23 (30 g fire assay with AAS finish).

Qualified Person

Andrew Ware, RM-SME, a Qualified Person as defined in NI 43-101 — Standards of Disclosure for Mineral Projects, and a senior consulting geoscientist to the Company, has reviewed and approved the technical disclosures in this news release. The Company adheres to CIM Best Practices Guidelines in conducting, documenting, and reporting exploration activities.

About Santo Tomás

Santo Tomás is an advanced-stage porphyry copper project in Choix, Sinaloa, Mexico. Oroco holds a net 87.0% interest in the 1,173-hectare Core Concessions and an 80% interest in surrounding concessions at Santo Tomás. The Project was tested by historical drilling from 1968 to 1994 and by Oroco’s Phase 1 program, which totaled 48,481 metres in 76 diamond drill holes and supported the revised Mineral Resource Estimate (“MRE”) and updated PEA.

The August 2024 MRE, prepared by SRK Consulting (U.S.), Inc., outlined an Indicated Resource of 540.6 Mt at 0.33% Cu, 0.008% Mo, 0.028 ppm Au and 2.1 ppm Ag and an Inferred Resource of 530.3 Mt at 0.31% Cu, 0.007% Mo, 0.023 ppm Au and 1.9 ppm Ag. The updated PEA, prepared by Ausenco Engineering USA South Inc., contemplates a staged open-pit operation ramping from 60,000 t/d in Year 1 to 120,000 t/d by Year 8 over a 22.6-year life of mine, generating an after-tax NPV8% of US$1.48 billion and an after-tax IRR of 22.2%. Both studies are available on SEDAR+ at www.sedarplus.ca and at www.orocoresourcecorp.com. The PEA is preliminary in nature; see “Cautionary Note” below.

About Oroco Resource Corp.

Oroco Resource Corp. is a Vancouver-based mineral exploration and development company advancing the Santo Tomás copper project in Sinaloa, Mexico.