The mill hole is a vertical opening and is usually lined with steel.
Not be critical, but in my days as a timberman at Giant, we raised a lot of millholes, always using timbers, never steel. Maybe the process has changed in the last 40 years or so! (the Giant Grizzlies also used wooden hockey sticks!)
Again I stand to be corrected, but it's unlikely they'll use raises in the near term, but will haul the ore blasted from the stopes developed in the Hinge directly to surface where they'll either stockpile or feed it into the mill. Same can be said for development ore which can be fed through the mill at any time.
In 1965, Giant whose geology was very similar to SAN, was trading at $12.00+.
IMHO, its just a matter of time.
RUF