Prime Mining Corp. Selects Ausenco for PEA Study on Los Reyes Project

VANCOUVER, British Columbia, May 27, 2025 — Prime Mining Corp. (“Prime” or the “Company”) (TSX: PRYM) (OTCQX: PRMNF) (Frankfurt: O4V3) has announced the selection of Ausenco Engineering Canada ULC (“Ausenco”) to lead the Preliminary Economic Assessment (PEA) study for its wholly-owned Los Reyes gold-silver project (“Los Reyes” or the “Project”) located in Sinaloa State, Mexico. The PEA is targeted for completion in the third quarter of 2025.

The PEA aims to reflect a high return, high margin, low capital, and long-life project at Los Reyes. It will be based on drilling data up to the end of 2024 and will incorporate extensive technical work completed to date. Since acquiring the Los Reyes project in 2019, Prime has invested over $64 million in direct exploration activities and has completed more than 221,000 meters of drilling.

Prime CEO, Scott Hicks, expressed enthusiasm about the project’s progress, stating, “We are excited to share that we are accelerating our work on a Preliminary Economic Assessment for the Los Reyes Project. This follows a recently completed, robust initial de-risking program of benchmarking.”

Company Overview

Prime Mining Corp. is a materials sector company based in Vancouver, Canada, specializing in precious metals mining services. The company focuses on environmental engineering, geological studies, exploration, processing, and development of gold and silver. Prime Mining serves customers exclusively in Canada and is listed on the Toronto Stock Exchange. As of May 21, 2025, the company’s close price was CAD 1.32, with a market capitalization of CAD 201,100,677. The 52-week high was CAD 2.32 on May 29, 2024, and the 52-week low was CAD 1.13 on November 12, 2024. More information about Prime Mining Corp. can be found on their website at www.primeminingcorp.ca .