Independent Proxy Advisory Firm ISS Recommends Arizona Sonoran Copper Company Shareholders Vote FOR the Arrangement with Hudbay Minerals

• The board of directors of ASCU unanimously recommends that Shareholders vote FOR the Arrangement Resolution
• Proxy voting deadline is May 7, 2026 at 1:00 p.m. (Toronto time)
• Shareholders who have questions or need assistance voting may contact ASCU’s proxy solicitation agent, Shorecrest Group Ltd., by phone at 1-888-637-5789 (North American toll-free) or 647-931-7454 (calls outside North America), or by email at [e-mail]

CASA GRANDE, Ariz. & TORONTO--(BUSINESS WIRE)--Arizona Sonoran Copper Company Inc. (TSX:ASCU | OTCQX:ASCUF) (“ASCU” or the “Company”) is pleased to announce that leading independent proxy advisory firm Institutional Shareholder Services Inc. (“ISS”) has recommended that shareholders of the Company (“Shareholders”) vote FOR the resolution (the “Arrangement Resolution”) to approve the proposed arrangement (the “Arrangement”) with Hudbay Minerals Inc. (“Hudbay”) at the upcoming special meeting of securityholders of the Company (the “Meeting”) to be held on May 11, 2026.

Under the terms of the Arrangement Agreement, each ASCU shareholder will receive 0.242 of a Hudbay common share for each ASCU common share held.

ISS Recommendation

In making its recommendation that Shareholders vote FOR the Arrangement Resolution, ISS noted:

“The proposed merger is strategically sound, as the combined entity is expected to benefit from a strengthened financial position and increased liquidity.”

Recommendation of the Board

As previously communicated, following the unanimous recommendation of the independent directors of the Company, the board of directors of the Company (the “Board”) unanimously determined that the Arrangement is in the best interests of the Company and is fair to the Shareholders (other than Hudbay and its affiliates). Accordingly, the Board unanimously recommends that Shareholders vote FOR the Arrangement Resolution.

Voting and Meeting Details

The proxy voting deadline is at 1:00 p.m. (Toronto time) on May 7, 2026, or 48 hours (excluding Saturdays, Sundays and holidays) prior to any adjournment or postponement of the Meeting.

The Meeting will be held at https://virtual-meetings.tsxtrust.com/1920 in a virtual-only meeting format via live audio webcast online at 1:00 p.m. (Toronto time) on May 11, 2026. Only securityholders of record at the close of business on March 25, 2026, are eligible to vote their securities virtually or by proxy at the Meeting. The management information circular and related Meeting materials have been filed by the Company on SEDAR+ and are available under its profile at www.sedarplus.ca and the Company’s website at www.arizonasonoran.com.

QUESTIONS? NEED HELP VOTING?

If you have any questions or need additional information regarding the voting of your common shares you should contact your financial, legal, tax or other professional advisor, contact ASCU’s shareholder proxy solicitation agent, Shorecrest Group Ltd., by telephone at 1-888-637-5789 (North American toll-free) or 647-931-7454 (calls outside North America), or by email at [e-mail].

About Arizona Sonoran Copper Company (www.arizonasonoran.com | www.cactusmine.com)

ASCU is a copper exploration and development company with a 100% interest in the brownfield Cactus Project. The Cactus Project, on privately held land, contains a large-scale porphyry copper resource and a recent 2025 PFS proposes a generational open pit copper mine with robust economic returns. Cactus is a lower risk copper developer benefitting from a State-led permitting process, in place infrastructure, highways and rail lines at its doorstep and onsite permitted water access. The Company believes that Cactus has the potential to become a significant contributor of copper production directly to the U.S. domestic supply chain. The Company is led by an executive management team and board which have a long-standing track record of successful project delivery in North America complemented by global capital markets expertise.