This part answers the question why they didn't drill the 171 million tonnes of Inferred resource.

2012 Exploration Program
The 2012 exploration program was designed specifically to avoid any work (diamond drilling,metallurgical test work, etc.) on the Schaft Creek deposit which if successful would have dictated a suspension to update that portion of the Feasibility Study. The objective of the 2012 exploration program was to test the mineral potential of the Schaft Creek Mineral Trend to host additional copper deposits. This trend is located on the west side of Mount LaCasse and extends for a distance of approximately 7 kilometres north of the Schaft Creek deposit.