Sierra Minerals Inc.
TSX : SIM

Sierra Minerals Inc.

March 10, 2008 08:01 ET

Sierra Intersects 90 Metres @ 1.59 g/t Gold at Cerro Colorado, Mexico

New Zone Identified Between Existing Ore Bodies

TORONTO, ONTARIO--(Marketwire - March 10, 2008) - Sierra Minerals Inc. ("Sierra" or the "Company")(TSX:SIM) is pleased to report recent assay results from its ongoing drill program at the 100% owned Cerro Colorado Gold Mine in Sonora, Mexico. These results include some of the highest value intercepts reported to date at Cerro Colorado over large widths, including drill hole GM-157 which intersected 90 m grading 1.59 g/t gold and 1.46 g/t silver from a depth of 28 m below surface. This hole included 26 m of 4.71 g/t Au and 2.2 g/t Ag, and was drilled through the eastern extension of the Breccia Central ore zone and indicates a significant increase in the width of the zone at this point. In addition, drill hole GM-153 intersected 44 m grading 0.9 g/t Au and 9.61 g/t Ag, and drill hole MCC-11 intersected 50 m grading 1.15 /t Au and 9.71 g/t Ag.

To date, the Company has completed over 14,000 m of drilling in 195 holes for the purposes of resource definition, exploration and ground sterilization drilling. Of the total holes, 154 have been drilled for resource calculation, of which 47 are summarized in this release. Holes identified as "MCC" were drilled by Major Drilling Group International (TSX:MDI), who commenced drilling in the fourth quarter of 2007.

A summary of significant results from the most recent set of assays is as follows, and all assay results and location maps can be seen on the website at www.sierraminerals.ca:



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HOLE Northing Easting From To Interval Au Ag
No. (metres) (metres) (m) (m) (m) (g/t) (g/t)
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GM 142 420175 3344098 46 52 6 0.36 2.47
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GM 153 420480 3344091 70 114 44 0.90 9.61
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GM 157 420559 3344158 28 118 90 1.59 1.46
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including 58 84 26 4.71 2.2
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GM 158 420556 3344183 38 78 40 0.67 2.37
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including 48 64 16 1.11 2.26
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GM 173 420504 3344377 36 74 38 0.48 3.23
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MCC 1 420905 3344333 16 26 10 0.21 0.18
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and 192 230 38 0.26 0.72
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MCC 2 420647 3344113 100 104 4 0.81 2.75
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MCC 3 420303 3343996 116 120 4 0.63 2.75
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MCC 11 420457 3344145 56 106 50 1.15 9.71
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including 62 84 22 2.14 6.21
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Note: The above intersections are un-cut and collar coordinates are in NAD27 Zone 13 Mexico datum. Most drill holes were drilled at a dip of 60 degrees, which is roughly perpendicular to the dip of the known ore systems. True widths are approximately 90 % of the reported widths. At the Cerro Colorado mine site, Sierra has implemented a quality control program to ensure best practices in chemical sampling and analysis of surface and drill core samples. All assaying for the holes reported was completed by International Plasma Laboratories of Richmond BC Canada and was independently checked by the Company's on-site mine assay laboratory. Under the guidelines of the NI 43-101, the required qualified person for the Cerro Colorado Gold Mine is Mr. Stephen Wetherup of CCIC, who is a professional geologist registered in British Columbia, Canada. Mr. Wetherup has reviewed and approved the technical aspects of this release.

Life of mine production at Cerro Colorado has been at an average grade of 0.82g/t, from four known ore zones namely Sorpresa, Harris, Abejas and Breccia Central with the Obra X ore body yet to be exploited. Exploration drilling has been concentrated in the main East West structure which hosts the Sorpresa, Breccia Central and Obra X mineralization and has thus far encountered a zone of previously unknown gold mineralization between the Sorpresa and Breccia Central ore bodies. Future drilling will focus on further definition of the new zone of mineralization and extensions of the known ore bodies. Sierra also controls a large land package in excess of 30,000 hectares surrounding Cerro Colorado where Sierra's geologists have identified other rhyolitic intrusives similar to those at Cerro Colorado.

About Sierra

Sierra is a gold producer focused on expansion by acquiring and developing advanced stage gold and silver deposits that have a likelihood of realizing near-term production. The Company's focus is Mexico, where it owns and operates the Cerro Colorado Gold mine. Sierra is committed to company-wide environmental and corporate social responsibility best practices.

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