May 23, 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 that a new gold anomaly (“Pinchanzo zone” or “Pinchanzo”) has been discovered less than 2 km south of the El Capitan gold zone currently being drilled (2,500 meter diamond core drill program) by Sierra Madre. This new epithermal gold area called the Pinchanzo zone has initial surface assay samples (21 samples) returning up to 2.38 g/t gold with 20 percent of the samples returning greater than 1 g/t gold. A follow up mapping and sampling program is now underway.

The Pinchanzo zone may define a further mineralized gold system on the 350 km² Peñoles Project located in northern Durango State, Mexico. This newly defined area consists of abundant silicification, chalcedonic quartz and similar volcanic sequences as seen at El Capitan. Seventeen of the 21 samples returned values greater than 100 ppb Au and up to 2380 ppb gold. Samples are representative composite rock chips of siliceous float material each collected from a 5 to 10 meter-diameter area. The Pinchanzo zone is localized along the NE side of a north to northwest trending low relief feature. Abundant silica occurs within a distinctive 150 to 300 meter wide band over a strike length in excess of one kilometer. Click here to view property map: http://bit.ly/KbuLJO

This encouraging new gold anomaly builds on previously completed regional soil sampling conducted earlier in the year. Further work on the Pinchanzo zone will commence immediately with more soil sampling, trenching, and potential drilling once targets have been better defined.

Soils-Float Reconnaissance Sampling

The previous 2011-2012 regional soil sampling tested three target areas that are located approximately 6, 9, and 10km south of the main El Capitan gold zone. The targets were defined with 10 north-south oriented soil lines designed with a sampling spacing of 50 meters (m), and line spacing of 200m. A total of 386 samples were collected along these lines with soil samples of chalcedonic silica returning low order trace element anomalies of Au-Ag-Zn-Cu-As-Mo. Float samples collected during this sampling program returned encouraging results with five of 10 samples reporting gold values ranging from 169 to 695ppb Au.

El Capitan Drilling

A second drill rig has now been mobilized to site for Sierra Madre. After completion of the resource drilling at El Capitan, Sierra Madre plans to test additional target areas at Peñoles. Current resource drilling is testing the Main El Capitan Zone. The El Capitan target area is described in the SEDAR filed NI-43-101 report as a hot-spring style gold system. Results of current drilling will be released as they become available.

Sierra Madre is pleased to report that this district continues to demonstrate significant upside potential as the company continues its exploration program. The recent field work has helped to further define some of this potential with the discovery of the new gold anomaly at the Pinchanzo zone. Riverside and Sierra Madre are now working closely together to advance drilling and exploration work on this 350 km² Peñoles Project located right in the heart of a historic mining region.

Assaying and Qualified Person:

All the samples from the composite rock chip sampling program carried out by Mark Roden on behalf of Sierra Madre on the new Pinchanzo zone were submitted to Inspectorate Laboratories prep lab in Durango City with pulps transported to Inspectorate’s assay facility in Sparks Nevada. The package used for the composite rock samples was SP-RX-2K (Aqua Regia Digestion with trace level detection limit) and one assay ton fire assay atomic absorption analysis for gold. Inspectorate Laboratories included a total of four blank, standard and duplicate analyses in the assay procedure.

All the samples from the regional soil sampling program (386 soil samples and 10 float samples) were submitted to ALS Chemex Lab in Guadalajara, Mexico for sample preparation and then sent to Vancouver for analytical assays. The package used for soil samples was ME-MS 41 L (Aqua Regia Digestion with ultra-low detection limit) and for float samples Au AA23 + ME ICP 41. ALS Chemex Laboratories included a total of 21 standard materials were inserted and 16 duplicate samples in the assay analysis procedure to comply with QA QC protocol.

The scientific and technical data contained in this news release pertaining to the Peñoles Project were prepared under the supervision of Mark J. Pryor, Pr.Sci.Nat, an independent 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 on the Company’s projects can be found on the Riverside Resources Inc. website at www.rivres.com.


"John-Mark Staude"

Dr. John-Mark Staude, President & CEO