American Bonanza drills test Copperstone (April 25, 2005)

Underground drilling by American Bonanza Gold (BZA-T) is testing the D zone as part of a broad effort to upgrade known resources at the past-producing Copperstone gold project in Arizona.

Copperstone operated as an open-pit mine from 1987 to 1992, during which time it produced about 500,000 oz. gold. The average grade was 0.1 oz. gold per ton.

American Bonanza recently drilled 68 holes and intends to sink eight more. The best hole returned a 9.8-metre intersection (true thickness) grading 41.6 grams gold per tonne. Other notable results include 3 metres grading 52.8 grams gold, 3 metres of 15.6 grams, and 4.5 metres of 35.7 grams.

Gold mineralization at Copperstone occurs in sedimentary and volcanic rocks in northwest-striking fault zones but is restricted to the fault zones. Little or no mineralization occurs in the wallrocks.

Exploration and development will target the mineralized faults to follow up along strike and dip from the current results, and from previously drilled mineralization.