Riverside Resources Inc.
TSX VENTURE : RRI
PINKSHEETS : RVSDF
FRANKFURT : R99

Riverside Resources Inc.

June 27, 2012 10:50 ET

Riverside Resources and Partner Sierra Madre Announce Additional Drill Results at the Penoles Project in Durango, Mexico

VANCOUVER, BRITISH COLUMBIA--(Marketwire - June 27, 2012) - Riverside Resources Inc. (TSX VENTURE:RRI)(PINKSHEETS:RVSDF)(FRANKFURT:R99) ("Riverside" or the "Company") and its partner, Sierra Madre Developments ("Sierra Madre") (TSX VENTURE:SMG), are pleased to announce additional drill results from the 2012 drill program at the El Capitan Target (a bulk tonnage oxide gold deposit), which forms part of the Company's Peñoles Project in Durango, Mexico. Drilling in 2011 demonstrated good continuity over a strike length of approximately 700 meters (referred to as the Main zone - see press release dated October 24, 2011) and the current program (funded by Sierra Madre) is designed to test the down-dip extent of mineralization and provide sufficient drill-hole density for an initial resource calculation for El Capitan.

The recently completed holes, CDDH 12-03 and CDDH 12-04, were drilled from separate drill pads in the central and west central parts of El Capitan. CDDH 12-03 (drilled on the same section as CDDH 11-16 and 11-17) returned 65.5 meters of 0.606 g/t gold and confirmed the presence of the previously unrecognized "upper mineralized zone" localized within the porous volcanic agglomerates overlying the main mineralized zone at El Capitan (reported in CDDH 12-01 and 12-02). Although the mineralization within the upper zone is not as continuous as the mineralization within the Main zone, the average grade of the entire drill hole (138.1 meters) is 0.349 g/t Au. CDDH 12-04 (drilled on the same section as CDDH 11-01) returned 44.2 meters averaging 0.670 g/t Au and also confirmed the presence of the upper mineralized zone. Results from CDDH 12-03 and 12-04 are shown in the table below (the true widths of the mineralized intercepts have not yet been determined, but are believed to be approximately 90% of true width):

Drill Hole From (m) To (m) Interval (m) Au (g/t)
CDDH 12 - 03 6.8 138.1 131.3 0.349
Including 68.7 134.2 65.5 0.606
Including 86.2 126.2 40.0 0.783
CDDH 12 - 04 107.8 152.0 44.2 0.670

Drilling at El Capitan is continuing and assays will be released as they are received. Preliminary results of the 2012 program are considered significant because El Capitan appears broadly similar to Argonaut Gold's El Castillo Mine located approximately 90 kilometers south of El Capitan. Argonaut Gold is successfully heap leach mining El Castillo at an average grade of 0.32 g/t Au with a cut-off grade of 0.15 g/t Au.

As previously announced (see press release dated October 12, 2011) preliminary bottle roll tests indicated that the mineralization at El Capitan may be amendable to low-cost cyanide leach extraction. To determine optimal leaching procedures Inspectorate Exploration and Mining Services of Richmond, BC has initiated systematic column leach testing utilizing approximately 1,200 kilograms of half core from the 2011 drill program.

There are ten other targets on the Peñoles Project including the recently announced Pinchanzo Zone (see press release dated May 23, 2012), potential west extensions of El Capitan (referred to as the West Extension), a new target area located to the northwest of El Capitan (referred to as Santa Theresa or Capitan Northwest Zone), and the previously mined Jesus Maria and San Rafael Ag-Au-Pb-Zn mines. Extensive surface sampling has been completed on several of the gold targets located near El Capitan and results will be announced as they become available. The district is highly prospective, with active mining operations nearby, and has proven to be a safe and cost-effective region where projects can be efficiently developed towards production.

Assaying and Qualified Person:

All drill core was placed in numbered boxes and transported to Sierra Madre's secure core facilities by the drill contractor. Following detailed core logging all core was split using a diamond-bladed core saw under the direct supervision of Sierra Madre's geologic staff. Half of the core was kept onsite in the original core boxes, and the second half was placed in labeled and sealed sample bags that were transported directly to the custody of Inspectorate, a laboratory certified for the provision of assays and geochemical analysis (ISO:9001-2008). Samples were transported to Inspectorate's facilities in Durango, Mexico for prep work and analyzed at their facilities in Reno, Nevada. All samples were prepared using standard industry prep methods followed by fire assay analysis and aqua regia digest for trace elements. All samples with greater than 10 g/t Au were additionally tested by fire assay with a gravimetric finish. Sierra Madre has included 10% industry certified Au standards and blanks within the sample stream in addition to field duplicates as part of the QA/QC program. All quality-control sample results were within acceptable control limits.

The scientific and technical data contained in this news release pertaining to the Peñoles Project were prepared under the supervision of Carl Von Einsiedel, a qualified person to Sierra Madre, and reviewed by David S. Smith, MS, MBA, CPG, a qualified person to Riverside Resources, who are responsible for ensuring that the geologic information provided in this news release is accurate, and who act as "qualified persons" under National Instrument 43-101 Standards of Disclosure for Mineral Projects.

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 $9,000,000 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 on the Company's projects can be found on the 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.

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