The Henderson deposit is composed of two partially overlapping ore bodies beneath the summit of Red Mountain. The ore bodies are entirely within a Tertiary rhyolite porphyry intrusive complex that has intruded the Precambrian Silver Plume granite. The mineralization is relatively continuous in the ore bodies and consists of molybdenite and quartz in random intersecting closely spaced veinlets. The Henderson mine is a porphyry molybdenum deposit with molybdenite as the primary sulfide mineral.

The Henderson operation consists of a large block-cave underground mining complex feeding a concentrator with a current capacity of approximately 32,000 metric tons per day. The available underground mining equipment fleet consists of fifteen 9-metric ton load-haul-dump (LHD) units and seven 73-metric ton haul trucks, which deliver ore to a gyratory crusher feeding a series of three overland conveyors to the mill stockpiles.

The Henderson mine is located in a mountainous region with the main access shaft at 3,180 meters above sea level. The main production levels are currently at elevations of 2,200 and 2,350 meters above sea level.

The Henderson mine and mill are connected by a 10-mile conveyor tunnel under the Continental Divide and an additional five-mile surface conveyor.

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Henderson has the capacity to produce approximately 15 million pounds of molybdenum per year. The majority of the molybdenum concentrate produced is shipped to our Fort Madison, Iowa, processing facility.

The mine and the Mill are connected by a fifteen-mile elevated belt that passes underneath the Continental Divide through an old train tunnel and then above ground to the mill. Molybdenite (the molybdenum containing mineral) is obtained from the ore by crushing, grinding, and flotation.