Excelsior is developing a low cost copper project within the copper porphyry belt of Arizona. Based on an initial production rate of 110 million pounds per year and a US$2.75/lb copper price, the Prefeasibility Study indicates a pre-tax NPV7.5 of US$1.24 billion, pre-tax IRR of 59.7% and a payback period of 1.8 years. Total initial capital expenditures (including contingency) are estimated at US$284.84 million with sustaining capital (including an acid plant) of US$602 million and an average life-of-mine direct operating cost of US$0.69/lb. These metrics are amongst the lowest per pound capital and operating costs for copper projects in North America.

Over 60,000 metres have been drilled to date on Gunnison, which has a Probable Mineral Reserves of 3.61 billion pounds (632 million tons at 0.29% copper) contained within the Measured and Indicated Mineral Resources of 3.91 billion pounds (683 M tons at 0.29%). There is also an additional Inferred Mineral Resource of 1.40 billion pounds (338 million tons at 0.21%). Please refer to the Projects page for further information on the mineral reserve and mineral resource estimates and results of the Prefeasibility Study.