May 23, 2012 (ACCESSWIRE-TNW via COMTEX) — May 23, 2012 – Vancouver, BC: Sierra Madre Developments Inc. (“Sierra Madre” or the “Company”) /quotes/zigman/2993952 CA:SMG -6.25% and its partner Riverside Resources Inc. (“Riverside”) /quotes/zigman/478675 CA:RRI -1.47% 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 km? Penoles 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 was identified by long time prospector Mark Roden and is localized along the NE side of a north to northwest trending low relief topographic feature. Abundant silica float occurs within a distinctive 150 to 300 meter wide band over a strike length in excess of one kilometer.

To see the El Capitan and Pinchanzo zones on a property map go to the following link:

http://sierramadredevelopments.com/el-capitan-and-pinchanzo-oxide-gold -target-areas/

This encouraging new gold anomaly builds on previously completed regional exploration work conducted earlier in the year. Further work on the Pinchanzo zone will commence immediately with detailed mapping, sampling and trenching and if warranted drill testing after high priority target areas have been better defined.

Regional Soils – Reconnaissance Sampling

During late 2011 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 (equivalent to 0.169 to 0.695 g/t gold).

El Capitan Drilling

A second drill rig has now been mobilized to site for Sierra Madre. After completion of infill drilling at the El Capitan Main Zone Sierra Madre plans to test additional target areas at Penoles. 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 program 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. Sierra Madre and Riverside are now working closely together to advance drilling and exploration work in the historic Penoles District.

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 Penoles Project were prepared under the supervision of Carl von Einsiedel, P.Geo. CEO of Sierra Madre. Mr. von Einsiedel is the non-independent qualified person to Sierra Madre Developments, 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 Sierra Madre Developments: Sierra Madre is a TSX Venture listed junior mining company based in Vancouver, British Columbia, Canada. Management has extensive exploration and mining expertise and the Company’s business model is to acquire advanced gold and silver projects and build shareholder value by rapidly advancing our projects through the resource delineation stage.


“Carl von Einsiedel” Carl von Einsiedel, President & CEO

For additional information contact: 604-685-3357

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.


Our company BYLSA DRILLING provides drilling services in a variety of environments, ranging from typical exploration sites to extreme topographic conditions, always with the highest quality and safety standards.