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

 

June 4, 2012 � Vancouver, BC: Riverside Resources Inc. ("Riverside" or the "Company") (TSX-V: RRI) and its partner, Sierra Madre Developments (�Sierra Madre�) (TSX-V: SMG), are pleased to announce drill results including 20.9 meters of 1.01 g/t gold from the first two drill holes completed as part of the 2012 drill program at the El Capitan Target (a bulk tonnage oxide gold target), which forms part of the Company�s Pe�oles  Project in Durango, Mexico. Drilling in 2011 tested approximately 60% of the strike extent of the zone and the objective of the current drill program (funded by Sierra Madre) is to test the down-dip extent, further test the westward strike extension, and provide sufficient drill hole density for an initial resource calculation on the El Capitan gold zone. 

The first two holes of the new drill program at El Capitan, CDDH 12-01 and CDDH 12-02, were drilled in the central part of the known mineralized zone between CDDH 11-02 and CDDH 11-18. These two new holes returned some of the widest mineralized intervals encountered so far at El Capitan. Drill hole CDDH 12-01 was a vertical hole and terminated in mineralization at a depth of 123.1 meters. The second drill hole (CDDH 12-02) was drilled at an inclination of -80 degrees to explore the down-dip extent of mineralization and intersected a 141.5-meter-wide mineralized zone. Results from the first two drill holes are shown in the table below. (The true widths of the mineralized intercepts have not yet been determined.)

Drill Hole	From (m)	To (m)	Interval (m)	Au (g/t)
CDDH 12 - 01	12.65	123.1	110.45	0.365
Including	32.7	123.1	90.40	0.430
Including	95.1	116.0	20.9	1.011
CDDH 12 - 02	13.55	155.1	141.55	0.305
Including	120.55	141.35	20.8	0.727

Three distinct, mineralized rock units have now been defined at El Capitan. The upper part of the mineralized zone consists of a porous, volcanic agglomerate cut by narrow quartz veinlets and hydrothermal breccias (averaging 0.2-0.5 g/t Au). At the base of the volcanic unit there is a shallow dipping, 10.0- to 35.0-meter-wide silicified zone (averaging 0.7 to 1.5 g/t gold) and below this zone there is a sequence of oxidized shales that is also cut by quartz veinlets and hydrothermal breccias (averaging 0.2-0.6 g/t Au).  The system is low-sulfidation epithermal style with relatively low silver values so far averaging about 1-4 g/t Ag at the El Capitan body, but in other zones on the property there is high-grade silver (100-500 g/t Ag) commonly with lead, zinc, and copper.

The results of CDDH 12-01 and 12-02 confirm that mineralization continues down dip from the area tested in 2011 and indicate that the upper part of the mineralized zone is almost flat lying. Although widely spaced, step-out holes drilled down dip by Riverside in 2008 suggested that the upper contact of the mineralized zone was shallowly dipping; preliminary drilling results indicate that mineralization is in fact much closer to surface than had been anticipated. 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 Argonaut Gold Inc. is currently heap-leach mining the nearby El Castillo deposit (a low-grade oxide gold deposit averaging 0.32 g/t gold with a cut-off grade of 0.15 g/t Au). El Capitan so far appears broadly similar to El Castillo in geology, geochemistry, and geomorphology, as both Castillo and Capitan are hills held up by low-temperature silica. This is common for gold deposits in this part of Mexico, and Riverside and Sierra Madre continue to explore for similar targets on the broader Pe�oles Project.

There are up to ten other targets on the Pe�oles  Project including the recently announced Pinchanzo zone (see press release dated May 23, 2012) and the previously mined Jesus Maria and San Rafael Ag- Au-Pb-Zn mines. 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. Several geologists are currently onsite conducting a detailed evaluation of the Pinchanzo Target, and significant results will be announced as they become available. 


Assaying and Qualified Person:
According to Sierra Madre, 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, 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 Pe�oles 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.


"John-Mark Staude"

Dr. John-Mark Staude, President & CEO