Early in 2002, drill testing of a geophysical anomaly resulted in the discovery of the massive sulfide deposit. Subsequent drilling in 2002-03 and 2006-08 totaling over 77,000 meters has defined numerous closely spaced zones of significant zinc-gold-copper-silver mineralization comprising the Back Forty Deposit.

The January 2009 NI 43-101 Compliant Resource Statement includes 8.5 million tonnes in the measured and indicated categories and 1.17 million tonnes inferred category. This includes open pit resources of 4.66 MT measured of 3.64% zinc and 2.04 g/t gold, 1.26 MT indicated of 5.63% zinc and 4.03 g/t gold, and 620,000 tonnes inferred at 2.46% zinc and 3.68 g/t gold and underground resources consisting of 1.06 MT measured at 9.23% zinc, 1.51 MT indicated at 9.11% zinc, and 550,000 tonnes inferred at 6.62% zinc. Net smelter return cut-off values averaging US$20 per tonne for open pit ores, and US$62 per tonne for underground ores were used to calculate the resource.