Riverside Resources and Questcorp Mining Execute Definitive Option Agreement for La Union Project, Sonora, Mexico

Riverside Resources Inc. (TSXV: RRI) (OTCQB: RVSDF) (FSE: 5YY) ("Riverside" or the "Company"), is pleased to announce that further to its press release dated September 6, 2024, Riverside's wholly-owned subsidiary, RRM Exploracion, S.A.P.I. DE C.V. (the "Vendor") has entered into a definitive option agreement (the "Option Agreement") with Questcorp Mining Inc. ("Questcorp") dated May 5, 2025, for the 2,520.2 hectare La Union carbonate replacement gold- polymetallic project (the "Project" or "La Union") located in Sonora, Mexico (the "Transaction").

"We are thrilled to finalize this agreement for the La Union Project, which is a strong asset in Riverside's portfolio. Securing up to C$5,500,000 in exploration funding from Questcorp is an excellent step forward in advancing this larger Carbonate Replacement Deposit ("CRD") project," said John-Mark Staude, CEO of Riverside Resources. "Riverside is pleased to have the updated NI 43-101 Technical Report completed and we see an active exploration program launching in the coming weeks with Riverside as the Operator of the exploration program. Riverside is expected to become a shareholder of Questcorp with an initial 9.9% equity interest, subject to final approval by the Canadian Securities Exchange or confirmation that such approval is not required. The first-year work program of C$1,000,000 in exploration expenditures will launch the first round of exploration at the project."

The La Union Project

The Project is summarized on the Riverside website and is a project that Riverside acquired and further consolidated additional inlier mineral claims. The Project initially identified from Riverside's work in the western Sonora gold belt through work with AngloGold Ashanti Limited, Centerra Gold Inc., and Hochshild Mining Plc, among others as partners and funding relationships for gold exploration. Initial work by members of the Riverside team, drawing on more than two decades of geological compilation and analysis, identified this region as highly prospective. At the Project, historical mining by the Penoles Mining Company focused on chimney and manto replacement bodies within the upper oxide zones. As a result, the underlying sulfide zones present immediate drill targets for further exploration.

Riverside has spent the past five years consolidating this highly prospective land package, which totals over 22 square kilometers. The Project features favorable limestone host rocks, an extensive alteration footprint, and multiple small-scale historical workings, providing more than eight drill-ready target areas. Key immediate targets include the central Union Mine and the nearby Famosa Mine. With drive-up access, private ranch surface rights, and strong geologic similarities to other major CRDs in Arizona and eastern Mexico, La Union is well positioned for near-term exploration success targeting both oxide and deeper sulfide mineralization.

The Option Agreement

In accordance with the terms of the Transaction, Questcorp can acquire a one-hundred percent (100%) interest in the Project in consideration for completion of a series of cash payments totaling $100,000 CAD, making staged issuances of common shares of Questcorp totaling 19.9%, and incurring $5,500,000 CAD of exploration expenditures on the Project as outlined immediately below:

During the term of the Option Agreement, Riverside, through the Vendor, will remain the program operator for the Project using its local team based in Hermosillo, Sonora. Following exercise of the option under the Option Agreement, Questcorp will grant Riverside a two-and-one half percent (2.5%) net smelter return royalty on commercial production from the Project.

Figure 1. Geologic map with the tenure of the Union internal concession shown in pink. Manto and chimney type CRD targets are shown as red polygons. Riverside now controls all mineral tenures on this map.

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Figure 2. Cross section looking west with proposed drill sites and drillhole traces. Assays from Riverside's sampling of rock dump materials from the two mine areas are labeled in black. Red areas are interpreted as manto and chimney target bodies that are now well defined and drill ready. Assays shown on figures 1 and 2 have been previously released and disclosed as summarized below the geochemical QA/QC. 

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Qualified Person & QA/QC:

The scientific and technical data contained in this news release pertaining to the Project was reviewed and approved by Freeman Smith, P.Geo, VP Exploration, 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.

Rock samples from previous exploration programs discussed above at the Project were taken to the Bureau Veritas Laboratories in Hermosillo, Mexico for fire assaying for gold. The rejects remained with Bureau Veritas in Mexico while the pulps were transported to Bureau Veritas laboratory in Vancouver, BC, Canada for 45 element ICP/ES-MS analysis using 4-acid digestion methods. A QA/QC program was implemented as part of the sampling procedures for the exploration program. Standards were randomly inserted into the sample stream prior to being sent to the laboratory.

About Riverside Resources Inc.:

Riverside is a well-funded exploration company driven by value generation and discovery. The Company has over $4M in cash, no debt and less than 75M 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. These statements can be identified by the use of forward-looking terminology (e.g., "expect"," estimates", "intends", "anticipates", "believes", "plans"). Such information involves known and unknown risks -- including the risk that the Transaction will not be completed as contemplates, or at all, availability of funds, the results of financing and exploration activities, the interpretation of exploration results and other geological data, or 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.

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