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

Riverside Resources Inc.
Sierra Madre Developments Inc.
TSX VENTURE : SMG

Sierra Madre Developments Inc.

July 19, 2012 09:15 ET

Riverside Resources and Partner Sierra Madre Extend Main Zone at El Capitan Target in Durango, Mexico

VANCOUVER, BRITISH COLUMBIA--(Marketwire - July 19, 2012) - Riverside Resources Inc. ("Riverside" or the "Company") (TSX VENTURE:RRI)(PINKSHEETS:RVSDF)(FRANKFURT:R99) and its partner, Sierra Madre Developments (TSX VENTURE:SMG) are pleased to announce results of two step-out holes (CDDH 12-12 and CDDH 12-13) drilled approximately 50 meters to the east of the area referred to as the Main Zone of the El Capitan Target (see press release dated October 24, 2011). Results of CDDH-12 and CDDH 12-13 include some of the widest and best grade intervals encountered to date within El Capitan. CDDH 12-13 is a vertical hole drilled from a station approximately 50 meters east of CDDH 11-07 and CDDH 12-11 and intersected mineralization from surface to a depth of 130.20 meters. The entire hole returned an average grade of 0.555 g/t gold, including a 61.15 meter section that averaged 0.919 g/t gold. The hole was stopped in mineralization, which is open at depth below this hole. CDDH 12-12 was drilled at an inclination of 60 degrees from the same pad and intersected mineralization from surface to a depth of 161.8 meters. The entire drill hole averaged 0.329 g/t gold and included a 29.31 meter interval that averaged 0.737 g/t gold. The true thickness of these mineralized intervals is estimated to be approximately 90% of the reported core lengths. The eastern part of the Main Zone has returned the widest mineralized intervals encountered so far at El Capitan and appears to be open for expansion down dip of CDDH 12-13. Additional drilling in this area is planned upon completion of the current program.

Table 1: Assay results for CDDH 12-12 and CDDH 12-13

Drill Hole Inclination From (m) To (m) Interval (m) Au (g/t)
CDDH 12 - 12 -60 0.00 161.80 161.80 0.329
Including 112.69 142.00 29.31 0.737
CDDH 12 - 13 90 0.95 131.15 130.20 0.555
Including 39.15 100.30 61.15 0.919

The following link http://rivres.com/sierra-madre-developments-and-partner-riverside-resources-extend-main-zone-at-el-capitan-target-in-durango-mexico is a plan view map that shows the locations of all drill holes reported to date within the "Main Zone" of the Capitan deposit.

El Capitan is a near-surface, shallow-dipping, oxide gold deposit exposed in the side of a low ridge that forms part of the Company's Peñoles Project in Durango, Mexico. Drilling in 2011 (18 holes), indicated potentially economic grade mineralization over significant widths (30 to 110 meters) and good continuity of the mineralized zone over a strike length of approximately 700 meters. Drilling so far in 2012 has confirmed that mineralization extends up to 250 meters down dip from surface and has identified a previously unrecognized "upper mineralized zone" in the rocks overlying the Main Zone (please refer to the Company's press releases dated June 04, June 27 and July 12, 2012).

Preliminary results of the 2012 program are considered significant because El Capitan appears broadly similar to Argonaut Gold' 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 gold 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 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 on site in the original core boxes, the second half was placed in labeled and sealed sample bags which 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.

The scientific and technical data contained in this news release pertaining to the Peñoles Project were prepared under the supervision of Carl Von Einsiedel, PGeo., a qualified person to Sierra Madre, and reviewed by David S. Smith, MS, MBA, CPG, a qualified person to Riverside Resources, who is responsible for ensuring that the geologic information provided in this news release is accurate and acts as a "qualified person" 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 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.

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