American Bonanza’s Copperstone delivers the high-grade

Vancouver – Development drilling by American Bonanza Gold Mining (BZA-V) at its wholly owned Copperstone project in La Paz Cty., Arizona has returned high gold values.

Underground core drilling, focused on upgrading D-zone indicated and inferred resources to measured resources and reserves, is about half-way through the planned program of 76 holes totalling 7,300 metres.

Drilling of the Copperstone fault, in east and northeast fan patterns on 15-metre centres from an underground drill station, continues to demonstrate the high-grade nature of the gold mineralization. Results from the core program include:

• Hole CUDH04-26 3.3 metres grading 51.2 grams gold per tonne and 0.7% copper, including a high grade intercept of 1.1 metres of 102.1 grams gold and 0.6% copper;
• Hole CUDH04-29 4.9 metres of 13.1 grams gold, including 1 metre of 37 grams gold;
• Hole CUDH04-31 5.8 metres averaging 8.3 grams gold and 0.9% copper, including a copper-enriched intersection of 0.8 metre returning 33.4 grams gold and 2.7% copper;
• Hole CUDH04-32 4.6 metres grading 25.4 grams gold and 0.6% copper, including a high-grade section of 1.1 metres of 83.6 grams gold and 0.8% copper.

A drill program targeting known high-grade on the Highwall zone also continued to encounter significant gold intercepts, including hole CRD04-08 with 3 metres averaging 48 grams gold, including 1.5 metres of 91.5 grams. Progress is about 15% complete with 15 holes totalling almost 4,400 metres conducted.

Gold mineralization at the deposit occurs in the sheared and altered Copperstone fault zone within a volcano-sedimentary rock package.

Copperstone was a former open-pit producer, operated by Cyprus Minerals from 1987-1992, with total output of about 500,000 oz. gold. The average grade was 3.8 grams gold per tonne.

A preliminary assessment report conducted in 1999 reviewed an indicated resource of 809,000 tonnes grading 11 grams gold per tonne (285,700 oz. gold) on the C and D-zones. An additional inferred resource of 1.08 million tonnes of 12 grams gold (423,000 oz. gold) was also outlined.

Investors were keen on the results, pushing the stock up over 10% to close at 21.5 on a volume of 1,457,000 shares at presstime. The latest report from the company shows 176.3 million shares outstanding.