Rio Grande Acquires the Golden Shrew Property, British Columbia

Rio Grande Mining Corp.

Suite 1128, 789 West Pender Street Vancouver, BC, V6C 1H5 Tel: (604) 669-9330 Fax: (604) 669-9335

FOR IMMEDIATE RELEASE August 10, 2012

RIO GRANDE ACQUIRES THE GOLDEN SHREW PROPERTY, BRITISH COLUMBIA

Vancouver, BC, August 10, 2012: Rio Grande Mining Corp. (RGV - TSX-V) (the “Company”) is pleased to announce that it has negotiated an option to acquire, subject to TSX Venture Exchange acceptance, a 100% interest in three mineral claims consisting of 880.5 hectares, located in the New Westminster Mining Division, British Columbia, and known as the Golden Shrew claims (the “Property”).

The Property is located approximately 80 kilometres east northeast of Vancouver, British Columbia, about 6 kilometres north of Chehalis Lake which lies 8 kilometres west of Harrison Lake. The Property is accessible north from Highway 7 over approximately 30 kilometres of seasonal logging roads.

Float boulders containing massive and banded pyrite, pyrrhotite, sphalerite with minor chalcopyrite and arsenopyrite over a distance of 540 metres demonstrate good potential for copper-lead-zinc volcanogenic mineralization in the area. In 1976 and 1977 exploration work was carried out by Chevron. Further prospecting and geochemical sampling were carried out in 1991 and 1992.

On a regional scale, the volcano-sedimentary strata found between Harrison Lake and Chehalis Lake area contains two distinct episodes; Middle Jurassic Harrison Lake Group in the south and Lower Cretaceous Fire Lake Group in the north. These two lithological packages are separated by shales and volcaniclastic sediments of the Middle Jurassic Mysterious Formation and Upper Jurassic Billhook Formation. The Harrison Lake fault and Fire Creek thrust form major northwest trending fault structures to the northeast of the Shrew showing.

Much of the showing is underlain by a sequence of highly faulted felsic to intermediate volcanics and associated agglomerates, tuffs, shales and sandstones of the Harrison Lake Formation. These are overlain by finely banded tuff and argillite of the Echo Island Member and grey to black shale and argillite of the Mysterious Creek Formation. A fault bound sliver of dacitic to rhyolitic tuff and andesitic flows of the Lower Cretaceous Brokenback Hill Formation occurs along the northern edge of the claims. Bedding of the units is generally very flat with dips to the west and southwest of approximately 20 to 45 degrees. These units have been intruded by feldspar porphyry and quartz diorite plugs.

Two types of mineralization occur at the Property. Extensive skarn mineralization and hornfels occur along the northwest trending contact between the Harrison Lake Group and Echo Island Member. The skarn and hornfels are mineralized with massive coarse pyrite, pyrrhotite and minor arsenopyrite. This mineralization is confined to at least three northeast trending faults of limited extent and gossanous zones.

The terms of the option are as follows:

• $5,000 due on signing of the option agreement;
• $20,000 and 300,000 common shares due to the optionor upon acceptance of the option agreement by the TSX Venture Exchange;
• $25,000 and 300,000 common shares due to the optionor on the first anniversary of the option agreement;
• $25,000 and 300,000 common shares due to the optionor on the second anniversary of the option agreement.

The Property will be subject to a 2% NSR royalty in favour of the optionor.

Mr. James A. McCrea., P. Geo., a Qualified Person as defined by NI 43-101, has reviewed this news release and approves all scientific and technical disclosure.

On behalf of the Board of Directors,

John Bevilacqua President & CEO Rio Grande Mining Corp.

(604) 669-9330

Neither 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.