This vertical section of Jeffery Mine shows the two processes for extracting the ore: open-pit and subterranean. In the open-pit method, the only one in present-day use, the asbestos is near the surface; after drilling and excavating, the unrefined ore is trucked to the grinding mill. In the subterranean method, miners must go down into the earth. Once it has been drilled, the ore is loaded onto carts and hauled up to the surface.
