Commonwealth Silver Announces Initial NI 43-101 Mineral Resource Estimate at Commonwealth Project in Arizona

4.75 Million Ounces Silver and 290,000 Ounces Gold Indicated Mineral Resources (17.6 Million Tonnes at 43.8 g/t Ag and 0.51 g/t Au)

1.25 Million Ounces Silver and 11,000 Ounces Gold Inferred Mineral Resources (1.1 Million Tonnes at 35.7 g/t Ag and 0.31 g/t Au)

TORONTO, ONTARIO -- (Marketwire - Oct. 11, 2011) - Commonwealth Silver and Gold Mining Inc. ("Commonwealth Silver" or the "Company") is pleased to announce that it has received the results of its initial National Instrument 43-101 ("NI 43-101") compliant, independent mineral resource estimate completed by SRK Consulting (U.S.), Inc. ("SRK") at its Commonwealth silver and gold project in Cochise County, Arizona, approximately 120 km (75 miles) southeast of Tucson. The effective date of the estimate is October 6, 2011.


Mineral Resource Statement for the Commonwealth Silver-Gold Deposit,
Cochise County, Arizona, SRK Consulting (Inc), October 6, 2011*

Resource     Tonnes  Au Grade  Ag Grade  AgEq Grade     Contained Metal (Ounces)
Category     ('000)    (g/t)     (g/t)     (g/t)       Au         Ag         AgEq
Measured           0   0.00      0.00      0.00        0           0           0
Indicated     17,598   0.51     43.75     70.40     290,000   24,752,000   39,829,000
Measured + 
Indicated     17,598   0.51     43.75     70.40     290,000   24,752,000   39,829,000
Inferred       1,089   0.31     35.74     51.94      11,000    1,251,000    1,818,000

*Notes:
(1) Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the Mineral Resources estimated will be converted into Mineral Reserves estimate.

(2) Resources stated as contained within a potentially economically minable open pit stated above a 26.0 g/t Ag Equivalent cut-off.

(3) Pit optimization is based on assumed gold and silver prices of US$1,350/oz and US$26.00/oz, respectively, metallurgical recoveries of 90% and 75% for gold and silver, respectively and a mining, processing and G&A cost of US$19.50/t.

(4) Mineral resource tonnage and contained metal have been rounded to reflect the accuracy of the estimate, and numbers may not add due to rounding.

(5) Mineral resource tonnage and grade are reported as diluted to reflect a potentially minable bench height of 3.0m.

(6) Silver Equivalent stated using a ratio of 52:1 and ounces calculated using the following conversion rate: 1 troy ounce = 31.1035 grams. Metallurgical recoveries are not accounted for in the silver equivalent calculation


Michael Farrant, President and Chief Executive Officer stated, "We are extremely pleased to have accomplished this significant milestone. We initially set out to confirm an historic mineral resource estimate calculated by Behre Dolbear Group Inc. in 1996. SRK's current estimate has certainly exceeded our initial expectations and confirms our confidence in the Commonwealth Project. As we plan to go public, this NI 43-101 compliant mineral resource estimate will serve to establish a minimum valuation for the Company. Our next exploration efforts will focus on growing this mineral resource estimate and exploration of our Blue Jeep and San Ignacio targets within close proximity to the Commonwealth Project. As a Company, we have continued to deliver against our originally stated plans and I am very pleased with the work that continues to be performed by our team in Arizona."

The mineral resources for the Commonwealth silver-gold deposit, located in Cochise County, Arizona, have been estimated by SRK at 17.598 million tonnes grading an average of 0.51 g/t gold and 43.75 g/t silver classified as Indicated mineral resources with an additional 1.089 million tonnes grading an average of 0.31 g/t gold and 35.74 g/t silver classified as Inferred mineral resources. The resource is stated above a 26.0 g/t silver equivalent cut-off and contained within an open pit.

The mineral resources are reported in accordance with Canadian Securities Administrators ("CSA") NI 43-101 and have been estimated in conformity with generally accepted Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") "Estimation of Mineral Resource and Mineral Reserves Best Practices" guidelines. Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the mineral resource will be converted into mineral reserves.

The mineral resources are reported at a cut-off grade to reflect reasonable prospects for economic extraction. SRK considers that portions of the Commonwealth silver-gold deposit are amenable to open pit extraction. The "reasonable prospects for economic extraction" requirement referred to in NI 43-101 was tested by designing a series of conceptual open pit shells using the Lerchs-Grossman optimizing algorithm. After review of several scenarios considering different metal prices, SRK assumed a long-term gold price of US$1,350/oz and a silver price of US$26.00/oz. Other parameters include metallurgical recoveries of 90% and 75% for gold and silver, respectively; mining costs of US$1.50/t mined; processing and G&A costs of US$18.00/t processed, and pit-slope angles of 50º in all areas. These parameters were selected by SRK to represent an optimistic expectation reflecting the intent that the resource should comprise material that has the potential to be economically mineable. The reader is cautioned that the results from this pit optimization are used solely for the purpose of reporting mineral resources that have reasonable prospects for economic extraction by an open pit.

This initial mineral resource estimate is based on a 3D geologic model constructed using assay data from 17,700 meters of drilling in 172 drill holes and 2,998 meters of channel sampling in 209 channel sample lines. The raw assay data has been examined for the presence of high grade outlier data which could potentially adversely impact the grade estimation. Based on this analysis, all raw gold and silver assays were capped at 9.0 g/t and 300.0 g/t, respectively. The capped assay data were then composited into 3.0m downhole lengths for use in grade estimation. Block grades were estimated using inverse distance weighting ("IDW") interpolation methods.

This initial current mineral resource estimate has been completed by Jeffrey Volk, MSc CPG, FAusIMM, Principal Resource Geologist with SRK Consulting (U.S.), Inc., who has reviewed pertinent geological information in sufficient detail to support the data incorporated in the mineral resource estimate. Mr. Volk is an Independent Qualified Person as defined under NI 43-101 and is responsible for the mineral resource estimate presented in this release. Mr. Volk has reviewed the content of this news release, and consents to the information provided in the form and context in which it appears.

A copy of the full Technical Report will be available on the Company's website at www.commonwealthsilver.ca within 45 days.


The Commonwealth Project

The Commonwealth Project is an advanced exploration development project located in the historic Pearce mining district in southeastern Arizona. Historically, the deposits mined at the Commonwealth Mine were high grade silver gold ores hosted in quartz veins and stockwork zones adjacent to the veins. Production began in 1895, with commercial scale mining of the high grade ores ending in the late 1920's. Small scale mining by property lessors continued through 1942. During this period of time, the Commonwealth Mine produced approximately 12 million ounces of silver and 138,000 ounces of gold, making it Arizona's second largest historic primary silver producer. The project was extensively explored and drilled by a number of companies from the 1970's into the mid-1990's who were seeking lower grade mineral resources amenable to open pit mining and heap leach extraction. Work reached the pre-feasibility study level in 1996 before being halted due to low gold and silver prices. No work was done on the project from 1997 to 2011 when Commonwealth Silver optioned the property and resumed exploration.

The mineral deposits on the Commonwealth Project are typical silver dominant, low sulfidation epithermal veins and stockworks. The veins are best developed in a series of Tertiary volcanic rocks of andesite to rhyolite composition correlative with the Mexican Lower Volcanic Series. Cretaceous marine sediments of the Bisbee Group also host mineralization and are chemically favorable hosts.

The two most important veins are the Main Vein and the North Vein. Between these two veins lies a wedge of volcanic rocks with well-developed quartz stockwork veining which is mineralized with silver and gold. The vein system has been mapped over 1 km of strike length and continues to the east under alluvial cover. Drilling has tested at least 800 meters of this strike length to a maximum depth of just over 200 meters. There is significant potential to find extensions to the known vein system both east, west and down dip. All the known veins in the district have a combined strike length of over 4.5 km.


About Commonwealth Silver and Gold Mining Inc.

Commonwealth Silver is a private Canadian mineral exploration and development company focused on acquiring gold and silver properties in the historic Pearce mining district in Cochise County, Arizona and advancing them towards production. The Company comprises an experienced management group with a strong background in all aspects of acquisition, exploration, development and financing of precious metals mining projects.

For further information on Commonwealth Silver please visit www.commonwealthsilver.ca.


CAUTIONARY NOTE REGARDING FORWARD LOOKING INFORMATION

This news release contains certain "forward-looking information" under Canadian securities laws. All statements that address future plans, activities, events or developments that the Company believes, expects or anticipates will or may occur are forward-looking information. This can include, but is not limited to comments regarding the timing and expectations for finalizing property agreements, timing and content of upcoming work programs, geological interpretations, receipt of property titles, potential mineral recovery processes etc. Forward-looking information addresses future events and conditions and therefore involves inherent risks and uncertainties. There can be no assurance that outcomes anticipated in the forward-looking information will occur and actual results may differ materially from those currently anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking information. The Company undertakes no obligation to update publicly or otherwise any forward-looking information, except as may be required by law.

No stock exchange, regulation securities provider, securities commission or other regulatory authority has approved or disapproved the information contained in this news release.



Contact Information

Commonwealth Silver and Gold Mining Inc.
Michael Farrant, President & CEO
416-278-4149
Toll free: 1-855-645-7471
mfarrant@commonwealthsilver.ca

Commonwealth Silver and Gold Mining Inc.
Donald Greco
Vice President, Corporate Development
416-909-4500 or Toll free: 1-855-645-7471
www.commonwealthsilver.ca