Sendero Resources rebuilds Peñas Negras assay database across 77 historical holes

Sendero Resources Rebuilds Peñas Negras Drill Assay Database, Applying Consistent CuEq Methodology Across 77 Historical Holes

(TheNewswire)

Highlights

Hole PNDH-06 intersected 44 metres grading 1.23% CuEq within 236 metres of 0.57% CuEq

Hole PND-02 intersected 43.6 metres grading 1% CuEq within 208 metres of 0.56% CuEq

Hole PNR-30 intersected 18 metres grading 1.26% CuEq within 161 metres of 0.54% CuEq

Hole PNDH-03 intersected 62 metres grading 0.66% CuEq within 268 metres of 0.49% CuEq

Hole PNDH-04 intersected 52 metres grading 0.61% CuEq within 266 metres of 0.48% CuEq

Hole PNR-03 intersected 52 metres grading 1.26% CuEq within 68 metres of 1.15% CuEq

Hole PNR-28 intersected 32 metres grading 1.95% CuEq within 102 metres of 0.93% CuEq

Vancouver, British Columbia – (September 23, 2026) – TheNewswire - Sendero Resources Corp. (TSXV: SEND) (FSE:9O40) (the “Company” or “Sendero”) is pleased to report a review and the recalculation of Metal Equivalents on historical drilling on the Peñas Negras copper-gold project in La Rioja province, Argentina. The Company has rebuilt the database from historical drill programs conducted by notable prior owners and operators evaluating 77 holes and 6,433 assay samples. Applying one consistent CuEq methodology across the entire historical database provides a broader, project-wide view of the project.

"For the first time, we have a consistent, project-wide depiction of the historical drilling at Peñas Negras, reinforcing why we're so excited about this project," said Jeremy Gillis, Interim CEO of Sendero. "Mineralization begins near surface and extends to more than 350 metres downhole, highlighted by 24 metres of 1.53% CuEq in PNDH-06. This work brings the full value of decades of prior exploration into focus, and we look forward to what is to come from our fully funded drill program."

Copper Equivalent (CuEq) values shown in the tables for drill