Riverside Resources Options Cecilia Project, Sonora, Mexico to Calu

VANCOUVER, British Columbia, Oct. 20, 2026 (GLOBE NEWSWIRE) — Riverside Resources Inc. (“Riverside” or the “Company“) (TSX-V: RRI) (OTCQB: RVSDF) (FSE: 5YY0), is pleased to announce that its subsidiary, Ravena Resources Corp. (“Ravena“), together with RRM Exploraciones, S.A.P.I. DE C.V., has completed an option agreement with 1559239 B.C. Ltd., operating as Calu Resources Corp (“Calu“) for the Cecilia Project in Sonora, Mexico. Under the agreement, Calu can earn 100% interest in the project by completing the business terms outlined below with a total earn-in work expenditure of $6,650,000. Ravena, the subsidiary of Riverside, will manage the exploration work and receive a 10% operations fee. The work will include an updated NI 43-101 report, followed by a firm commitment exploration program of at least C$150,000 in the first 12 months. Calu has made the initial payment of C$50,000 to Ravena to begin the option commitment. Calu is a new private company that intends to become public through a three-way amalgamation with Pender Capital. That transaction is described in a separate news release issued by Calu and Pender Street Capital Corp.

“Riverside is pleased to progress another property in its portfolio where Riverside retains a 2% NSR royalty and its subsidiary, Ravena Resources, receives option payments and acts as the operator of the exploration program,” said John-Mark Staude, CEO of Riverside Resources. “As we build our royalty portfolio, we are focusing on properties where discovery can add value to those royalties, particularly properties held through Riverside and, going forward, those included in the planned 2027 spin-out of Ravena Resources Corp. With more than C$6,500,000 in exploration expenditures under the earn-in, this agreement allows Cecilia to advance at no cost to Riverside.”

Option and Earn-In Terms

Under the Option Agreement, Calu may acquire a 100% interest in the Cecilia Project by making aggregate cash and share payments of C$1,200,000 and funding aggregate exploration expenditures of C$6,650,000 over five years, as follows:

Unless otherwise indicated, all amounts in this news release are expressed in Canadian dollars.

The initial C$50,000 cash payment and at least C$150,000 in exploration expenditures during the first 12 months are firm commitments of Calu under the Option Agreement. All remaining payments and exploration expenditures are optional, but Calu must complete them to keep the option in good standing and to exercise it.

Where permitted under the option agreement, Calu may elect, with at least 10 business days’ notice, to make all or part of a cash payment in Calu shares. The number of shares issued will be based on the 10-trading-day volume-weighted average price of Calu shares on a recognized stock exchange, subject to applicable securities laws and stock exchange policies. Shares will be issued fully paid and free of encumbrances, other than statutory resale restrictions.

Ravena will act as operator of all exploration programs on the Cecilia Project during the option period and will be entitled to a management fee equal to 10% of eligible exploration expenditures.

The Cecilia Project is subject to an existing 2.0% net smelter returns royalty in favour of 1412597 B.C. Ltd., a subsidiary of Riverside Resources Inc. Upon exercise of the option, Calu will grant Ravena an additional 0.5% net smelter returns royalty. Calu will have the right to purchase the entire 0.5% royalty from Ravena for US$1,500,000 in cash at any time prior to January 1, 2035.

Cecilia Project

The Cecilia Project is located in northeastern Sonora, Mexico, approximately 40 kilometres southwest of Agua Prieta, near the Mexico-United States border, and 100km due east of the Cananea large copper mining complex. Operations of Couer Mining, First Majestic, Agnico Eagle, Grupo Mexico, Penoles, Hylander Silver are all active in the area around the Project. Riverside’s exploration work has included drilling at four key targets that warrant follow-up exploration. Six additional targets are permitted for drilling and could host a new discovery as well. If exploration is successful, Riverside will benefit through its royalty interests in addition to the option payments. The main concession block includes the Cecilia 1 titled claim and collectively covers > 60 km² of titled ground plus an additional 16 km² of application ground for a total property area of approximately 7,583 hectares (76 km²). Further information about the property has been provided previously and is available on the Riverside website.

Northern Miner Interview

John-Mark Staude, President and CEO of Riverside, and Julian Manco, Vice President of Exploration for Ravena Resources, discuss the planned Ravena spin-out with The Northern Miner in a sponsored video interview recorded at the Precious Metals Summit: https://www.northernminer.com/stock-markets-investing/sponsored-riverside-readies-mexico-spinout/1003895457/.

Corporate News – Options Grant

On September 4, 2026 the Company granted incentive stock options to purchase an aggregate of 1,650,000 common shares of the Company to certain directors, officers, employees and consultants of the Company, in accordance with the Company’s Stock Option Plan. The options are exercisable at a price of $0.41 per share for a period of five years, expiring September 4, 2031. Options granted to Director’s vest in three equal installments of 33% on the six-month, twelve month and eighteen-month anniversaries. Options granted to certain officers, employees and consultants vest in four equal installments of 25% of the common shares on the three-month, six-month, nine-month and twelve-month anniversaries. The grant is subject to the policies of the TSX Venture Exchange.

Qualified Person & QA/QC

The scientific and technical data contained in this news release pertaining to the Project was reviewed and approved by Julian Manco, P.Geo, a non-independent qualified person to Riverside Resources Inc., who is responsible for ensuring that the information provided in this news release is accurate and who acts as a “qualified person” under National Instrument 43-101 Standards of Disclosure for Mineral Projects.

About Riverside Resources Inc.

Riverside is a well-funded exploration company driven by value generation and discovery. The Company has a solid balance sheet with no debt and fewer than 95M shares outstanding with a strong portfolio of gold-silver and copper assets and royalties in North America. Riverside has extensive experience and knowledge operating in Mexico and Canada and leverages its large database to generate a portfolio of prospective mineral properties. Riverside has properties available for option, with information available on the Company’s website at www.rivres.com. 

ON BEHALF OF RIVERSIDE RESOURCES INC.

“John-Mark Staude”

Dr. John-Mark Staude, President & CEO

For additional information contact:

Certain statements in this press release may be considered forward-looking information, including statements regarding the Option Agreement, the planned exploration program, and payments and exploration expenditures to be made by Calu. These statements can be identified by the use of forward-looking terminology (e.g., “expects”, “estimates”, “intends”, “anticipates”, “believes”, “plans”). Such information involves known and unknown risks, including the risk that Calu does not complete the payments and exploration expenditures required under the Option Agreement, the risk that Calu’s proposed amalgamation with Pender Capital is not completed as contemplated, or at all, the value of any Calu shares issued as payment, availability of funds, the results of financing and exploration activities, the interpretation of exploration results and other geological data, unanticipated costs and expenses, and other risks identified by Riverside in its public securities filings, that may cause actual events to differ materially from current expectations. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.