Oroco increases South Zone certainty at Santo Tomás

VANCOUVER, British Columbia, June 18, 2026 (GLOBE NEWSWIRE) -- Oroco Resource Corp. (TSX-V: OCO; OTCQB: ORRCF) (“Oroco” or the “Company”) is pleased to report the second 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 S025, S026, S028 and S029 and are consistent with the 2024 Technical Report block model in the areas tested. “Our Phase 2 drilling continues to confirm a compelling copper resource at Santo Tomas with low capital intensity requirements. The results clearly support a near or at surface, low strip resource as defined in the August 2024 Technical Report.

The program is focused on increasing resource certainty in the South Zone to support the mine plan and a Pre-Feasibility Study, and that is what is being delivered,” stated Oroco President, Ian Graham. “The elevated grades in the area of the S018 drill pad further confirm early access development in the southwest part of the South Zone and, most notably, S031 has provided evidence of mineralization that extends beyond the inferred resource of the existing block model.” Highlights Hole S025 , a near-vertical hole collared on the same pad as S024, returned intervals consistent with the August 2024 Preliminary Economic Assessment block model (the “ PEA Block Model ”) and suggests stronger and thicker mineralization than was intersected in S024, including 84.94m at 0.29% Cu / 0.33% CuEq and 90m at 0.41% Cu / 0.53% CuEq. Hole S026 was drilled SSW from the same pad as S018 ( see May 21, 2026 news release) and returned 48.6m at 0.56% Cu / 0.67% CuEq, 59m at 0.2% Cu / 0.33% CuEq and 23.45m at 0.16% Cu / 0.24% CuEq. The higher-grade material was intersected in the shallower parts of the hole.

Hole S028 was drilled WSW from the same pad as S026 and t