The depth certainly limits the economics of these drill holes at Red Chris. However, some of their past drill results have returned >10% copper equivalent over great lengths (see here). It seems like most underground mines are profitable with 2-3% copper equivalent, so I'm sure that an underground mine at Red Chris would also be profitable.

Don't worry, I'm not here to pump Imperial Metals. I'm just saying that if it's possible for Schaft Creek to hit this type of mineralization somewhat closer to the surface then our share price would rocket. Again, I'm not a geologist so I don't know if it's possible. All that I know is that Red Chris and Schaft Creek are not very far apart.