Sterling is fairly typical of sediment-hosted, disseminated precious metal deposits, also termed Carlin-type deposits.

Gold occurs in the rims of microscopic pyrite grains (actually arsenian pyrite rims). The pyrite formed during hydrothermal alteration and brecciation resulting from the interaction between: gold-bearing solutions rising along high-angle fault feeders from depth; soluble carbonate rocks; and iron-bearing silty lithologies. The process was most effective at a site of permeability contrast or barrier, and was accompanied by decalcification and solution brecciation, and silicification and clay alteration in breccia clasts, matrix, and in the wall rocks. Subsequent oxidation of the pyrite converted it to iron oxide/hydroxide minerals but without removing gold particles, allowing heap leaching of the ore to extract the gold. Favourable geological conditions existed (1) in the original Sterling mine at the thrust contact (siltstone/phyllite structurally above dolostone, especially trending along intersecting fault feeders), and (2) in the 144 zone at the contact between silty dolostone of the basal Bonanza King and the underlying Carrara limestone. The clay-altered margin of a large, Tertiary quartz latite dike in the 144 zone was also conducive for high-grade gold mineralization. In all cases, mineralization is generally stratabound but discontinuous, and typically ranges in thickness from 5-10 ft to over 30 ft (2 to 9 m).

In the Sterling property in northern Bare Mountain, the Tertiary-age low-angle Fluorspar Canyon Detachment is also important as a control for mineralization at several gold deposits. These include the Bullfrog, Daisy, West zone, Secret Pass and Mother Lode deposits; past mining (by other operators) has yielded more than 3 million ounces of produced gold.

The proposed restart of the Sterling open pits would utilize common conventional small to medium sized open pit mining equipment that is readily available such as Cat 992 loaders and Cat 777 haul trucks which are a good match for the pit sizes.

The Sterling, Ambrose and Burro Pits would be pushed back and deepened. The Panama and Water Tank Hill pits would be new pits. Preliminary estimates show this project would extend the mine life another three years.

Sterling currently has a 3.7 acre heap leach pad that includes a carbon adsorption-desorption- recovery (ADR) plant for the purpose of recovering gold. This pad was completed in April 2012 which included liner installation and a drainage layer composed of minus ¾ inch gravel covering perforated drain pipes. The purpose of the drainage layer is to allow for equipment to travel on the pad without damaging the liner and to allow for solution to drain freely from the stacked ore.

A leach solution of sodium cyanide is used to dissolve gold from the ore, transforming the leachable gold into a pregnant solution. The leach solution is applied by way of pumps and distributed through a drip emitter system. The flow rate applied to an area of the heap is based on the industry standard application rate of 0.005 gpm/ft2 of heap surface area. The solution flows by gravity through the ore and is directed to a collection sump. The pregnant solution then exits the sump and is directed to the pregnant pond. The pregnant solution then passes through a closed carbon column circuit for adsorption of gold. There are 4 columns that operate in series where the barren solution from the previous column is the pregnant solution for the next column in the series. Once the activated carbon becomes loaded with gold, and recovery from the pregnant solution drops, the carbon is then transferred into a desorption column for stripping the concentrated gold off the carbon. A hot strip solution of alcohol, water and caustic soda is prepared and passes through the loaded carbon desorption column, causing the gold to go back into solution. The gold concentration in the desorption solution is 100 fold higher than the heap leach pregnant solution.

The desorption solution then passes through an electrowinning cell (E-Cell) where gold is precipitated onto steel wool cathodes. The concentration of gold in solution entering and leaving the e-cell is monitored every 2 hours. The analysis determines the efficiency of the e-cell and also indicates the quantity of gold being removed from the loaded carbon. When the gold grade in solution reaches a concentration less than 0.2 oz/ton the desorption process is complete. The steel wool is then allowed to dry for 24 hours in preparation for smelting and production of doré bars. The doré bars are then shipped to a smelter for refining and sale of the product.