In 1980, Westfield Minerals estimated a resource of the Zinc Zone totaling 67,132 tonnes grading 12% zinc and 280 g/t silver to a vertical depth of 137 m. The thickness was between 0.3 m and 3.7 m and averaged 1.4 m. The Zinc Zone with its associated mineralized envelope totaled 312,072 tonnes grading 3% zinc and 124 g/t silver with lead and gold credits to a vertical depth of 137 m. The thickness was between 3.6 m and 11.6 m and averaged 6.1 m. The Westfield estimate was supported by 48 drill holes totaling 5,160 m completed between 1953 and 1980.

In 1992, Noranda Exploration estimated a drill indicated figure of 90,718 tonnes averaging 8.3% zinc and 187 g/t silver averaging 1.5 m thick by 200 m long plunging steeply to the west.

The Westfield resource estimate is relevant as the most comprehensive historical resource; it is probably reliable based on the information and methods used in 1980. However it can only be considered as historical and significant, additional drilling is needed at the Zinc Zone to be compliant for NI 43-101 Resource standards.

In 1980, Lakefield Research estimated recovery and concentrate grades on the Zinc Zone at 97% zinc and 81% silver recovery that graded 59.4% zinc and 474 g/t silver in concentrate. In addition, 3% zinc and 12% silver was recovered in a pyrite concentrate that graded 1.8% zinc and 80 g/t silver.