Alteration and mineral assemblages throughout the deposit are represented by widespread argillic alteration, generally abundant alunite, and the presence of minor amounts of base metals, all of which indicate the ore deposits to belong to the high sulfidation (acid sulfate) class of epithermal mineral deposits. Fluid inclusion data indicates the solutions that deposited the coarse-grained quartz were dilute, with a salinity of 1-2 weight percent NaCl and temperatures ranging 200 to 300° C. Temporal relationships and the thickness of the tuff units suggest that the depth of formation was more than 900m. The geometry of the deposit is controlled by two dominant geologic features; favorable stratigraphic horizon, and structural connectivity to mineralizing fluids. In high sulfidation environments the fluids ascend via structural feeders and under acid attack particularly replaces more favorable units; in the case of Isabella Pearl the Guild Mine member of the Mickey pass Tuff was this unit.

The gold-silver mineralized zones discussed in this report include the Isabella, Pearl, and Civit Cat oxide deposits and the Pearl and Civit Cat sulfide deposits, collectively referred to in this report as the Isabella Pearl deposit. Alteration and mineral assemblages at Isabella Pearl, including widespread argillic alteration and generally abundant alunite, indicate the deposits belong to the high-sulfidation class of epithermal mineral deposits. K-Ar age determinations indicate the mineralization is about 19 Ma, some 7 to 10 million years younger than the age of the host rocks. This early Miocene age conforms to the age of other highsulfidation epithermal precious-metal deposits in the Walker Lane (e.g., Goldfield and Paradise Peak).

Silicification generally grades outward into argillization, which then grades into propylitically altered rocks. Silicification is localized by faults and shears, and in many areas, silica has replaced large masses of both the volcanic and granitic rocks. Gold is associated with this silicification, occurring primarily within the Guild Mine Member in the lower part of the Mickey Pass Tuff. This alteration assemblage is also present in the lower, more densely welded tuff characteristic of the Pearl deposit, but it is tightly confined around the mineralized core the deposit.

The Isabella mineralization is moderately argillized to highly siliceous, contains numerous vugs in former feldspar and pumice sites (vuggy-silica textures), and typically lacks any evidence of cross-cutting veinlets. Narrow, structurally controlled zones of silica-pyrite, as well as the more pervasive silica replacement bodies, generally grade outward into silica-kaolinite with local alunite envelopes, which in turn grade into pervasive illite-montmorillonite zones. The iron oxide minerals goethite, jarosite, and hematite are present in the siliceous groundmass. Gold occurs as very small (<10 microns) liberated particles in cavities and along fracture surfaces. Rare secondary minerals include barite, cinnabar, and scorodite. A nearhorizontal zone of pervasive argillic and advanced-argillic alteration occurs above the Isabella deposit in the upper, poorly to moderately welded rhyolitic ash-flow tuff of the Guild Mine Member. Within this altered zone, alunite occurs as pseudomorphs after potassium feldspar phenocrysts and as replacements of pumice fragments.

The Pearl deposit is hosted by the lower, densely welded portion of the Guild Mine Member and, to a lesser extent, by Cretaceous granite. Mineralization is largely controlled by the northwest- striking, northeast-dipping contact zone between the granitic basement and the overlying Tertiary volcanic units. This contact may be partially or entirely faulted; this report assumes the contact is marked by the fault. Strong silicification accompanies gold mineralization and is associated with fracture fillings and replacement of the welded tuff. The mineralization is usually associated with strong brecciation. Multiple stages of fracturing and brecciation with associated silicification have been observed in drill core.

Sulfide minerals at Pearl commonly exceed ten percent (by volume) and are composed primarily of crystalline grains and aggregates of pyrite, colloform banded “melnikovite”-type pyrite, and bladed marcasite (or pyrite after marcasite) in dark microcrystalline quartz. This quartz has replaced both the volcanic and intrusive host rocks. In the granite, alteration has resulted in the complete leaching of feldspars and ferromagnesian silicates, and pyrite and marcasite have filled the voids left by the silicate dissolution. Rare sulfide minerals observed in thin and polished sections include arsenopyrite, pyrrhotite, galena, sphalerite, chalcocite, chalcopyrite, polybasite, and pyrargyrite. Other minerals include very minor magnetite, zircon, monazite, and rutile. Native gold has not been observed in the sulfide mineralization.

The oxidation boundary is depressed over and immediately around the Pearl deposit, with oxide mineralization extending to more than 150 m (500 ft) below the surface. Goethite, jarosite, and manganese oxide are common, and barite and chlorargyrite occur rarely in the siliceous groundmass. Gold within the oxide mineralization occurs both as locked and liberated particles, as well as electrum. Particles range in size from 2 to 34 microns, averaging 14 microns. The liberated particles occur as small wire-like grains in cavities, while the locked gold is encapsulated by silica or goethite.

The Civit Cat mineralization, which is relatively minor and poorly defined by drilling, lies to the northeast of Pearl and is associated with the northwest-striking, southwest-dipping Civit Cat fault. The control on mineralization by the Pearl and Civit Cat faults, which have similar strikes but opposing dips, results in northwest-trending, roughly lens-shaped zones of mineralization that flank both sides of a graben-like structural trough.

The Isabella Pearl mine design consists of one pit accessing the Isabella, Pearl and Civit Cat North deposits. Open pit mining is conducted by conventional diesel-powered equipment, utilizing a combination of blasthole drills, wheel loaders, and 91-tonne (100-short ton) trucks to define, and handle ore and waste. Support equipment includes graders, track dozers, and water trucks. Higher-grade ore (>0.61 g/t Au) is hauled to the crushing area and crushed before being placed on the leach pad. Low-grade ore between 0.38 and 0.61 g/t Au is hauled directly to the low-grade stockpile. Waste rock is stored in the waste rock facility located in close proximity to the pit to reduce haulage costs.

The final pit was designed using 6 m (20 ft) benches with a bench face angle of 68°, and an inter-ramp slope of 49.7° between a triple bench-catch of 8 m (26 ft). Haul roads were designed to 14 m (46 ft) widths for one-way traffic and 24 m (79 ft) widths for two-way traffic. These widths included an external safety berm in compliance with Mine Safety and Health Administration (MSHA) regulations. The final location of the ramps was optimized in order to reduce the overall pit slopes in areas where the pit slope was required to be less than 50°.

All ore and waste are hauled utilizing a 91-tonne (100-short ton) truck fleet. Low-grade ROM ore was initially placed on the heap leach pad with only lime addition on pad areas protected by a minimum of four feet of cover over the leach pad liner and collector piping system. Most of this material was placed in interior portions of the heap leach to minimize the difficulty of re- grading for reclamation. Currently, high-grade ore is hauled to the crusher pad stockpile to then fed to the crusher by a front-end loader. The high-grade (formerly crushed) ore is then delivered to the heap by a stacker conveyor system. Low-grade ore is currently being stored in the low- grade stockpile for either future crushing or direct placement on the heap as ROM.

The mine pits will generate an estimated total of 15.8 million tonnes (17.4 million short tons) of waste rock. The dump face is at the estimated 40° angle of repose of the material. The Pearl dump is being built from the south toe upward, with the outer slopes concurrently graded to 3(Horizontal):1(Vertical). The outer faces of the graded waste are being contoured, compacted, overlain with growth medium and revegetated when it is practical. Contouring and re-vegetation of the top of the dump will occur during postproduction reclamation.

Isabella Pearl mining operations are being conducted by a contractor. Isabella Pearl production is scheduled to mine up to 600,000 tonnes (661,400 short tons) of material (ore and waste) per month from a 2-phase pit. The Pearl zone is mined in 2 phases (Pearl Phase 1 & 2) in order to balance the high strip ratio of the upper benches and maintain an adequate cash flow balance. The current plan targets WLMC to process an approximate average of 54,400 tonnes (60,000 short tons) of ore per month over the LOM. Major mining equipment currently includes one Caterpillar D8 dozer, one Caterpillar D9 dozer, two Caterpillar 14M motor graders, two 769 Caterpillar water trucks, two lube trucks and two mechanic’s trucks.

The mine is currently in operation 12 hours per day, 7 days per week (12/7). During production, mining operations require two crews operating on twelve-hour rotating shifts.

During mining operations, blasthole samples are collected and assayed to provide control for ore and waste segregation. The resulting information is used to assign a material type to the blocks representing the active benches. Each block is assigned a destination code based on classification of the material (highgrade ore, low-grade ore, and waste). Following assay and ore/waste designation, visual identification of waste is made by the site geologist and compared to the mine block model. The tonnage of this material is tracked by WLMC geologists and the mine production reporting system.

The Isabella Pearl higher-grade ore above the 0.61 g/t Au cutoff will be crushed to P80 5/8”. This will be accomplished with a two-stage portable crushing plant with a 250 tonne (276 short ton) per hour capacity.

The higher-grade ore will first be trucked from the open pit to a stockpile located close to the primary crushing circuit. A front-end loader will then feed the higher-grade ore to the crushing circuit. The ore will then be placed into a stationary grizzly located above the hopper that will prevent oversize material from making its way into the crusher cavity. A 1.2 m (4 ft) x 6.1 m (20 ft) vibrating grizzly feeder will draw ore into the jaw crusher. The minus 5 cm (2 in) grizzly feeder undersize material will bypass the crusher and will combine with the crusher product on the crusher discharge belt conveyor.

Primary crushed ore, at approximately 80 percent passing 7.6 cm (3 in), will be conveyed to a vibrating, inclined, triple deck screen. The undersize fraction from the screen will bypass the secondary circuit and will report to the fine crushing product belt conveyor. Screen oversize will be conveyed to the secondary cone crusher. Secondary crushed ore, at approximately 80 percent passing 1.6 cm (5/8 in) will be returned via conveyor to the triple deck screen. The undersize fraction from the screen is the product of the fine crushing circuit and will report to the fine crushing product belt conveyor. The product of the fine crushing circuit, will be either conveyed and stacked in a crushed ore stockpile or transported by a series of stacker conveyors to the heap leach pad. A series of several mobile, grasshopper-type conveyors will be added or removed as required dependent upon the stacking location on the pad. The final conveyor will be a radial-type mobile stacker that will place ore in lifts up to 8 m (26 ft) in height. Lime addition will be added at the first stacker conveyor by means of silo and screw feeder. All mechanical components of the crushing circuit will be semi-mobile, which will allow for a complete circuit relocation, when it is required. Water sprays will be utilized for dust suppression at the crusher feed hopper and at transfer points for the screen undersize material.

Metallurgical test work has validated that Isabella Pearl oxidized ores are amenable to gold and silver recovery by cyanidation. The most economically effective process has been identified as conventional heap leaching of crushed ore, and to a lesser extent ROM ore, followed by absorption/desorption recovery (ADR) and refining to produce doré bars. The estimated recovery of gold from all crushed ore is 81%. The estimated gold recovery of ROM ore previously placed on the heap leach is 60%.

The general layout consists of the heap leach pad area which covers about 114,000 m2 (1.5 million ft2 ) and provides containment for 3.1 million tonnes (3.4 million short tons) of ore. The leach pad is a modified valley fill with a double liner system. A berm ranging from 1 to 5 m (3.3 to 16.4 ft) has been constructed along the sides and downstream (south) edge of the pad. The ADR plant consists of five 2 m (7 ft) diameter vertical adsorption towers in series with a carbon screen on the ba ........