VANCOUVER, BRITISH COLUMBIA — (Marketwire) — 09/21/12 — Riverside Resources Inc. (TSX VENTURE:RRI)(PINKSHEETS:RVSDF)(FRANKFURT:R99) (“Riverside”) or the “Company”) reports agreed upon amendments to the Option Agreement between the Company and Sierra Madre on the Penoles Property in Durango State, Mexico. The amended Option Agreement is subject to TSX Venture Exchange approval.

As announced September 6, 2012, to earn a 51% interest in the Penoles Property (under the existing option agreement) Sierra Madre was required to make a cash payment of $250,000US to Riverside on September 30, 2012, a cash payment of $1,650,000US to Riverside on or before December 31, 2012, incur a total of $3,000,000 in exploration expenditures before May 31, 2013, make a $100,000 cash payment to Riverside on May 31, 2013 and also make a last $1,500,000 payment on or before May 31, 2013.

Under the revised terms of the Option Agreement, to earn a 51% interest in the Penoles Project Sierra Madre will be required to make a firm commitment of another $500,000 in exploration expenditures before March 31, 2013, make a $400,000 payment (firm commitment) on March 31, 2013 (payable in cash or shares at Sierra Madre’s election – share payments would be based on the 20 day VWAP and subject to TSX Venture Exchange approval). Then to keep the option in good standing Sierra Madre commits to making a $1,250,000 cash payment to Riverside on June 30, 2013, incur an additional $750,000 in exploration expenditures by September 30, 2013, make a $100,000 cash payment to Riverside on December 31, 2013 and make a final payment of $1,500,000 to Riverside on December 31, 2013 (payable in cash or shares at Sierra Madre’s election – share payments would be based on the 20 day VWAP and subject to TSXV approval). The $500,000 in expenditures and the $400,000 payment due by March 30, 2013 are firm obligations. The amended option agreement is subject to TSX Venture Exchange approval.

President and CEO, John-Mark Staude, stated: “We are pleased to have reached an agreement that works for Sierra Madre and Riverside to continue with the option and expand work in the ground. The firm commitment for payments helps Riverside recover some of the investment Riverside has made into the project, and we now look forward to aggressive broader property exploration at this large district,” Staude added.

About Riverside Resources:

Riverside is a well-funded prospect generation team of focused, proactive gold discoverers with the breadth of knowledge to dig much deeper. The Company currently has approximately $7,500,000 in the treasury and 35,000,000 shares issued. The Company’s model of growth through partnerships and exploration looks to use the prospect generation business approach to own resources, while partners share in de-risking projects on route to discovery. Additional property information about Sugarloaf and other assets that are available for partnership can be found on Riverside Resources Inc. website at www.rivres.com.

ON BEHALF OF RIVERSIDE RESOURCES INC.

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.

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.