Gold mineralization at Gold Springs is hosted by complex sheeted veins, breccias, and stockwork vein systems that are laterally extensive and locally form resistant ledges and ribs that protrude up to 10 metres above the surrounding ground surface and surrounding areas of mineralized wallrock. The veins contain quartz, adularia, and bladed calcite with minor sulfides (<2%) and represent a low sulfidation, epithermal gold-silver vein system. Trace element geochemistry for arsenic and antimony show relatively low values similar to other quartz-adularia epithermal vein systems. Gold and silver mineralization are hosted in quartz and quartzcalcite veins, breccias, and stockwork/sheeted vein zones surrounding the main vein systems. Mineralization is also seen in the footwall zones of the Jumbo resource in pervasive altered latite that exhibits limited amounts of veining. True thickness of the mineralized zones reaches up to 150 metres wide, with the strike length of the vein systems extending up to several kilometres.

The Jumbo Trend is located in the east-central part of the project area and consists of five previously identified target areas. The Jumbo Trend extends approximately 10 km.

The Grey Eagle target is characterized by a complex zone of intersecting veins trending north-south, northeast, and northwest within a north-northeast trending structural zone. The veins form a mineralized corridor ranging from 20 to over 75 metres in width, which is traceable on the surface for over 700 metres before being obscured by postmineral cover.

The leach material and waste will be drilled and blasted using a rotary crawl driller and ammonium nitrate fuel oil (ANFO) and transported in dump trucks. The tuff at Grey Eagle and in the southern portion of Jumbo will be ripped with a dozer and then transported with scrapers to the waste dump. The tuff in the northern portion of Jumbo will be drilled and blasted along with the leach material and waste.

Initially, leachable material from Jumbo will be trucked from the Jumbo pit to the crushing site near Jumbo. After size reduction, Jumbo leachable material will be transported to the Jumbo leach pad by conveyor, where it will undergo cyanide leaching, followed by gold recovery by the Merrill-Crowe process.

When mining at the Jumbo pit is complete and crushing of Jumbo leachable material are complete, the skid- mounted crushing equipment will be moved and set up at Grey Eagle. Leachable material from Grey Eagle will be put under leach while the last Jumbo leaching is completed.

The crushed material will be transported by a series of “jump” conveyors from the crushers to the heap leach pads, where it will be stacked into a "heap" on an impermeable liner and irrigated with an alkaline sodium cyanide solution to dissolve the gold and silver.

The leachate (pregnant solution) will be collected as it percolates out from the base of the heap and will be piped into the pregnant solution pond.
Pregnant solution will be treated within the Merrill-Crowe plant.

GRE has included a Merrill-Crowe plant for recovery of gold and silver from the pregnant solution. An Adsorption-Desorption Refining (ADR) plant may be preferred with low solution metal concentrations.

The first step within the Merrill-Crowe plant will be clarification to remove the suspended solids from gold/silver cyanide solution.

After passing through the clarifiers, the solution will be fed to the de-aeration tower, where a negative pressure generated by a vacuum pump removes dissolved oxygen from the solution.

Zinc will be used to precipitate the gold and silver from the cyanide solution.

Gold and silver precipitates will be collected within a recessed plate “precipitate filter press.”

The discharge solution from the filter press is a barren solution. The precipitate filters will be emptied on a weekly basis. Prior to opening, the filter will be purged with low pressure compressed air to remove the excess solution and partially dry the filter cake precipitate. The precipitate will be collected from the press and dried prior to refining.

Refining is a multistep process. The cake will first be dried, followed by retorting to remove any contained mercury. After completion of retorting, the cake will be mixed with appropriate fluxes and smelted in an electric melting furnace. Dore´ (a mixture of gold and silver) will be stored in a vault until shipment to a third party refinery.