High River Gold Mines Ltd.
TSX : HRG

High River Gold Mines Ltd.

June 26, 2008 17:00 ET

High River Gold Nearly Doubles Prognoz Silver Resource With "Updated" NI 43-101 Resource Estimate

TORONTO, ONTARIO--(Marketwire - June 26, 2008) - High River Gold Mines Ltd. ("High River" or the "Company") (TSX:HRG) is pleased to report the results of an "Updated" Canadian Institute of Mining, Metallurgy and Petroleum National Instrument 43-101 ("NI 43-101") compliant silver mineral resource estimate, completed by MICON International Limited ("MICON"), on the Prognoz Silver Project ("Prognoz"). The "Initial" NI 43-101 compliant Resource Estimate was reported in a press release dated January 8, 2008.

The "Updated" NI 43-101 mineral resource estimate, based on drilling on only two veins, Glavnoye and Boloto (of over 30 identified so far on the property) and on drilling completed only up to December 31, 2007, almost doubles the resources at Prognoz. As well, MICON evaluated the conceptual additional mineral potential for 16 other veins. This evaluation indicated that substantial potential exists to significantly increase resources on the Prognoz property.

- "Updated" NI 43-101 Resource Estimate:



---------------------------------------------------------------------
Indicated Resources
---------------------------------------------------------------------
Tonnage (t) Silver grade (g/t) Contained Silver (oz)
---------------------------------------------------------------------
4,490,000 704 102 million
---------------------------------------------------------------------


---------------------------------------------------------------------
Inferred Resources
---------------------------------------------------------------------
Tonnage (t) Silver grade (g/t) Contained Silver (oz)
---------------------------------------------------------------------
4,870,000 659 103 million
---------------------------------------------------------------------


The Glavnoye vein is 4 kilometres long and was drilled to 400 metres depth. The Boloto vein has a strike length of 3.1 kilometres and was traced to a depth of 240 metres. The average thickness of both veins is 2.3 metres. The potential exists to increase these Resources as both veins are open at depth and the Boloto vein is open along strike to the east.

- "Updated" Estimate of Conceptual Additional Mineral Potential:

-- 161 million to 369 million additional ounces of silver

This reflects the potential of 16 other known veins on the property which has not been included in the Mineral Resource Estimate. The evaluation of the potential for these veins was based on the results of mineral samples obtained during trenching and step-out exploration drilling. In total, more than 30 silver veins have been identified on the Prognoz property and some may prove to be as extensive as the two whose mineralization is currently included in the resource estimate.

Background

High River indirectly owns a 50% interest in the world-class Prognoz Silver Project, one of the largest and highest grade undeveloped silver projects in the world. Located in the Republic of Sakha (Yakutia) of the Russian Federation, the property covers 56 square kilometres and hosts over 30 high grade epithermal veins.

Extensive drilling and trenching has been conducted on the Prognoz property. During 2006 and 2007, High River's 85%-owned Russian subsidiary, OJSC Buryatzoloto ("Buryatzoloto"), drilled over 650 core holes (over 59,500 metres), completed 4 adits for a total of 187 metres and extracted a 17 tonne bulk sample for metallurgical testwork. Historical work consisted of 89 diamond drill holes (17,805 metres) and 317 trenches (17,756 metres).

In early January 2008, High River announced the results of the "Initial" NI 43-101 resource estimate on the Prognoz Silver Project:

"Initial" NI 43-101 Resource Estimate



---------------------------------------------------------------------
Indicated Resources
---------------------------------------------------------------------
Tonnage (t) Silver grade (g/t) Contained Silver (oz)
---------------------------------------------------------------------
3,500,000 636 71.5 million
---------------------------------------------------------------------


---------------------------------------------------------------------
Inferred Resources
---------------------------------------------------------------------
Tonnage (t) Silver grade (g/t) Contained Silver (oz)
---------------------------------------------------------------------
2,210,000 551 39.2 million
---------------------------------------------------------------------


The "Initial" NI 43-101 resource estimate was based on drilling only up to May 31, 2007 (including historical exploration results) and on drilling conducted only on the Glavnoye and Boloto veins. Drilling for the resource estimate consisted of 198 diamond drill holes, comprised of 121 holes drilled by Buryatzoloto up to May 31, 2007 and 77 historical holes.

High River and independent engineering consultant, MICON, the author of the NI 43-101 compliant resource estimate, believed that the potential to increase resources at Prognoz is substantial and indicated a conceptual additional mineral potential of 97 to 194 million ounces of silver, which reflected the potential of 16 other veins.

"Updated" NI 43-101 Resource Estimate



---------------------------------------------------------------------
Indicated Resources
---------------------------------------------------------------------
Tonnage (t) Silver grade (g/t) Contained Silver (oz)
---------------------------------------------------------------------
4,490,000 704 102 million
---------------------------------------------------------------------


---------------------------------------------------------------------
Inferred Resources
---------------------------------------------------------------------
Tonnage (t) Silver grade (g/t) Contained Silver (oz)
---------------------------------------------------------------------
4,870,000 659 103 million
---------------------------------------------------------------------


The "Updated" NI 43-101 resource estimate incorporates assay results from drilling up to December 31, 2007, including historical exploration results. In total, assay results from 331 diamond drill holes (53,022 metres) and 242 trenches (12,745 metres) are included in the "Updated" Resource estimate. A breakdown of the drilling incorporated in the "Updated" resource estimate is as follows:

Diamond Drilling (Glavnoye and Boloto Veins)



---------------------------------------------------------------------------
Glavnoye Vein Boloto Vein Total
---------------------------------------------
Holes Metres Holes Metres Holes Metres
---------------------------------------------------------------------------
Historical 67 13,400 10 2,000 77 15,400
---------------------------------------------------------------------------
2006 80 10,738 5 513 85 11,251
---------------------------------------------------------------------------
2007 124 18,743 45 7,628 169 26,371
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Basis for Resource Estimate 271 42,881 60 10,141 331 53,022
---------------------------------------------------------------------------


MICON stated that the resource estimate is not materially affected by any known mining, metallurgical, infrastructure, environmental, permitting, legal, title, tax, socio-economic, marketing, political or other relevant factors.

The Qualified Persons responsible for the calculation of this NI 43-101 compliant Resource Estimate are William J. Lewis, B.Sc., P. Geo. (APEGB # 20333, APEGM #20480, NAPEGG #1450, APGO #1522), a senior geologist with MICON based in Toronto, Canada, and Dibya Kanti Mukhopadhyay (MAusIMM), a senior mineral resource geologist with MICON based in Norwich, England.

Further Notes to the "Updated" NI 43-101 Resource Estimate:

1. The geologic model used a break-even, cut-off grade of 100 g/t Ag, calculated by MICON.

2. Assay results were capped at grades ranging from 1,710 g/t to 8,230 g/t depending on the zones sampled. Only 2.4% of the samples were affected by capping.

3. The block model grade interpolation was performed using ordinary kriging with dynamic anisotropy.

4. Mineral Resources were estimated following NI 43-101 and JORC guidelines. Indicated Resources were defined as that portion of mineralization drilled on 40 metre centres. Indicated Resource blocks were estimated based on a minimum of 3 samples. Inferred Resources were defined as that portion of mineralization defined by surface sampling and few drill hole samples. For Inferred Resources, the lower density of drill hole data does not provide enough confidence to predict grade continuity, only geologic continuity.

5. Mineral Resources that are not mineral reserves do not have demonstrated economic viability.

"Updated" Estimate of Conceptual Additional Mineral Potential

In addition to the Glavnoye and Boloto veins, more than 30 silver veins in total have been identified on the Prognoz property. As such, High River and MICON believe the potential to increase silver resources at Prognoz is substantial. MICON has provided an "Updated" estimate of the conceptual additional mineral potential which is based on approximately 80 diamond drill holes and approximately 100 trenches on 16 other veins. This potential is not included in the Resource Estimate.



----------------------------------------------------------------------
----------------------------------------------------------------------
Mineral Mineral Average Potential Potential
Potential Potential Silver Contained Contained
Range (t) Grade Silver Silver
(g/t) (oz) (t)
----------------------------------------------------------------------
Minus 30% 6,474,000 775.8 161,481,000 5,023
----------------------------------------------------------------------
9,249,000 775.8 230,688,000 7,175
----------------------------------------------------------------------
Plus 60% 14,798,000 775.8 369,091,000 11,480
----------------------------------------------------------------------
----------------------------------------------------------------------


Since the conceptual additional mineral potential of a property cannot be estimated to the same accuracy as a mineral resource it must be stated as a range. To calculate the range, MICON applied a factor of minus 30% for the down side and plus 60% for the upside potential. The upside potential factor is larger than the downside potential factor because of the possibility that the mineralized zones included in the potential resources will be similar in nature to, and as extensive as, the Glavnoye and Boloto zones. MICON also indicated that contributing to the upside potential is the possibility that additional veins related to existing veins could be discovered (off-splays and anastomosing vein branches).

It should be noted that the additional mineral potential of the Prognoz property is conceptual in nature and that there has been insufficient exploration conducted on the 16 veins to define a mineral resource. It is also uncertain if further exploration will result in the targets being delineated as mineral resources. The 16 veins included in the conceptual additional mineral potential evaluation are as follows: Dal'naya (D), Dal'naya-1,2 (D1), Krutaya (K1), Guk (G), Solnechnaya (S1), Osenn'aya (O1), Yuzhnaya-1 (Y1), Yuzhnaya-2 (Y2), Yuzhnaya-3 (Y3), Yuzhnaya-4 (Y4), Tikhaya (T1), Vesenn'aya-1 (V1), Vesenn'aya-2 (V2), Vesenn'aya-3 (V3), Udachnaya (U), and Boloto-2 (B2).

The depth of conceptual mineral potential evaluation, for those zones which have been explored, ranges from between 40 metres and 100 metres below the deepest samples collected from either trenches or drill holes, to a maximum vertical depth of either 100 metres below the sample point or 200 metres below the surface, whichever is reached first. This maximum depth was used as it corresponds approximately to 1/3 of the depth of the known mineralization of the Glavnoye deposit. The exception is the eastern flank of the Boloto 2 zone where the maximum depth is set at 230 metres based on the actual depth of the mineralization in the eastern portion of the Boloto deposit.

Because the current world-class size and grade resource estimate at Prognoz is based on only two of more than 30 veins existing on the property, MICON believes that that there is significant potential for resource growth from further exploration and that therefore, the current estimate of the conceptual additional mineral potential for Prognoz is conservative.

About High River

High River is an unhedged gold company with producing mines, mines under development, and advanced exploration projects in Burkina Faso and Russia. High River is bringing two new open-pit gold mines into production. The Taparko-Bouroum Gold Mine in Burkina Faso achieved commercial production in October 2007, and the Berezitovy Gold Mine in Russia is expected to achieve commercial production shortly. At full production, annual gold production is planned at 100,000 ounces at Taparko-Bouroum and is expected to exceed 100,000 ounces at Berezitovy. Combined with gold production from two underground mines in Russia, Zun-Holba and Irokinda, High River's attributable unhedged annual gold production is expected to exceed 300,000 ounces. In addition, the Company has three advanced exploration projects, the Bissa Gold Project in Burkina Faso, the world-class Prognoz Silver Project and the Chaya Nickel Project in Russia. These projects are expected to significantly add to the Company's shareholder value in the future.

Forward Looking Statements - This press release contains forward-looking statements based on current expectations. These forward-looking statements entail various risks and uncertainties that could cause actual results to differ materially from those reflected. Risk and uncertainties about the Company's business are more fully discussed in the Management's Discussion and Analysis published in the Company's Annual Report and in the Annual Information Form.

Contact Information

  • High River Gold Mines Ltd.
    Dan Hrushewsky
    Vice President, Investor Relations
    (416) 947-1440
    (416) 360-0010 (FAX)
    Email: info@hrg.ca
    Website: www.hrg.ca