Riverside Resources and Questcorp Consolidate Key Mineral Concession for Union Project, Sonora, Mexico

Vancouver, March 18, 2026 - Riverside Resources Inc. (TSXV: RRI) (OTCQB: RVSDF) (FSE: 5YY0) ("Riverside" or the "Company") is pleased to announce the successful consolidation of the Famosa Area with three mineral concessions within the Union Project district in Sonora, Mexico, through the completion of the final payment and transfer of mineral title from Pacific Comox S.A. de C.V. to Riverside's wholly owned Mexican subsidiary, RRM Exploración S.A.P.I. de C.V. This provides the Company with clear ownership and the ability to advance exploration and, potentially, move toward mining based on future development results.

The transaction completes the acquisition of three mineral concessions: La Famosa, Dana 7, and Dana 7 which form an important portion of the southern part of the Union Project district. These concessions are mineral titles 199006, 220840, and 220841, with validity extending from 1994 through 2044 and 2003 through 2053, respectively. This long-term validity and fully titled status fit with the rest of the district mineral titles that the Company is advancing through its spring 2026 mineral exploration program.

The concessions were originally secured through an exploration agreement signed in August 2021 between RRM Exploración S.A.P.I. de C.V. and Pacific Comox S.A. de C.V., which provided Riverside with an option to purchase the claims within a five-year period (2021-2026). With the completion of the final payment of US$125,000, Riverside has now exercised the purchase option, and the titles have been formally transferred to Riverside. The total consideration for the acquisition amounts to US$175,000, and notably no net smelter royalty ("NSR") or any other type of royalty is attached to this transaction.

"We are pleased to complete the consolidation of the Famosa area within the Union Project, securing full ownership with no royalty burden for the transaction on these key concessions," said John-Mark Staude, President and CEO, Riverside Resources Inc. "This strengthens our district-scale land position and provides greater flexibility as we continue advancing exploration at Union with our partner Questcorp."

The Famosa Area hosts carbonate replacement deposit (CRD) style mineralization and structurally controlled gold mineralization within dolomite and quartzite units, located in the southern portion of the broader Union Project district. The consolidation strengthens Riverside's land position within the Union district and supports ongoing exploration efforts targeting CRD-style gold-silver-polymetallic mineralization.

This transaction represents another step in the systematic advancement of the Union Project, where Riverside has been working in partnership with Questcorp under an option agreement that provides for up to C$5.5 million in exploration expenditures funded by Questcorp while Riverside retains equity exposure and a 2.5% net smelter royalty on the project. Previous exploration programs at Union have included geological mapping, geophysics, diamond drilling, and high-grade rock chip channel sampling that have confirmed the presence of gold- and polymetallic-bearing CRD-style and sediment hosted gold-style mineralization across multiple targets within the district. By securing the Famosa concessions outright, Riverside further consolidates its district-scale land position and enhances the exploration potential across the southern portion of the Union Project. The expanded control of mineral titles provides increased flexibility for future exploration programs and supports the continued advancement of the project with partner-funded exploration.

Further technical updates related to exploration activities at the Union Project will be provided as programs progress.

About the Union Project

The Union Project is a district-scale carbonate replacement deposit (CRD) exploration project located in Sonora, Mexico. The project hosts historical mining areas and multiple exploration targets associated with gold, silver, zinc, and lead mineralization within carbonate and structurally controlled settings. Riverside operates the project through its Mexican subsidiary while advancing exploration in partnership with Questcorp.

Qualified Person

The technical content of the news release has been reviewed and approved by Freeman Smith, P.Geo. (British Columbia), a qualified person under National Instrument 43-101 who is non-independent and the Vice President Exploration for the Company.

About Riverside Resources Inc.:

Riverside is a well-funded exploration company driven by value generation and discovery. The Company has a strong balance sheet with over C$5,000,000 cash, no debt and tight share structure with a strong portfolio of gold-silver, copper, and REE assets and royalties in North America. Further information about Riverside is 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

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 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.

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