The Tres Cruces property hosts gold deposits that have characteristics of a low- to intermediate-sulphidation type epithermal system. Epithermal gold-silver deposits are shallowly formed vein, stockwork, disseminated, and replacement deposits that are mined primarily for their gold and silver contents; some deposits also contain substantial resources of lead, zinc, copper, and/or mercury. Epithermal gold-silver deposits range in size from 10,000 to >1 billion tonnes and have gold contents of 0.1 to >30.0 g/t, and silver contents of <1 to several thousand g/t. Although epithermal deposits are commonly known for their high gold grades, many bulk tonnage deposits with as little as 1 g/t gold or less are presently being exploited by open-pit mining.

Gold mineralization at Tres Cruces is mainly associated with pyrite, with occasional traces of other sulphide minerals. The auriferous pyrite is very fine grained, gray to blackish gray (commonly called "fine black pyrite”) and is present as disseminations and in very thin veinlets that locally form areas of stockworks (Macedo et al., 2012). Black pyrite also occurs as rims on earlier pyrite forming a colloform-banded texture. Clemson (Battle Mountain Canada Ltd., Tres Cruces Staff, 1999b) noted colloform-banding for this stage of pyrite, often with repetitive oscillatory bands of sooty and crystalline pyrite. The late-stage black pyrite is directly associated with the main-stage gold event. Early formed, non-gold-bearing pyrite is coarsely crystalline, anhedral to euhedral, poikilitic, and is evenly disseminated through the andesitic rocks. A second stage, also coarsely crystalline, is subhedral to euhedral and occurs primarily in veinlets and fractures. In addition, minor amounts of marcasite, arsenopyrite, galena, stibnite, realgar, orpiment and enargite have been identified in some mineralized core. Some carbonate minerals and rhodochrosite are also found in areas of pyrite veining. Age of mineralization is bracketed between measured age dates of 25.1 Ma from andesite porphyry host rocks and 22.2 Ma from a post-mineral flow; however, there may have been multiple pulses of mineralizing fluids uring this period.

Advanced Mineral Technology Laboratory Ltd. (AMTEL), in a document by Battle Mountain Canada Ltd. Tres Cruces Staff (1999a) also completed a study on gold deportment on several core samples. The main forms of gold were found as free native grains, grains in pyrite and in gangue. AMTEL reports the microcrystalline pyrite contains very high concentrations of gold and arsenic (up to 141 g/t and 10%, respectively). There is a strong positive correlation of the gold in pyrite with its arsenic content. AMTEL also commented that the high surface area of the fine-grained pyrite would make it more susceptible to oxidation.

Gold deposition appears to have been controlled by both structural and stratigraphic features. Subvertical controls of the mineralization are located along the intrusive contacts of andesite porphyry and dacite porphyry bodies. Steeplydipping, commonly northeast-trending faults that cut the intrusive bodies may have provided deep-seated conduits for mineralizing hydrothermal solutions driven by heat from underlying magma. The rising high-pressure fluids caused the formation of breccia “pipes” containing fragments of sandstone that were carried up from older underlying rocks. Hydrothermal fluids carrying mineralization rose through the breccia and emanated laterally into adjacent flows, flow breccias and pyroclastic rocks. Rhyolitic pyroclastics in the upper part of the pile may have been less permeable than the underlying andesitic rocks, thereby causing the mineral-rich hydrothermal fluids to pool under the rhyolite and spread laterally for considerable distances. Decreasing temperature and/or pressure of the hydrothermal fluids initiated the deposition of gold and sulphide minerals within stockwork veins in the fractured host rocks. Mineralization has been found to extend only short distances into andesitic and dacitic intrusive rocks, which may be due to lower permeability or less favorable chemical characteristics.

The Tres Cruces deposit contains both oxide and sulphide mineralization. Gold-bearing sulphide mineralization is mainly hosted in the older andesitic pyroclastic rocks and to a limited extent in andesite porphyry. The rhyolites also host mineralization but only near or along the andesite–rhyolite contact. Most of the rhyolite hosted mineralization along this contact has been oxidized, possibly due to strong fracturing of the siliceous rhyolite, which allowed deep circulation of surface waters. The underlying andesitic rocks have developed only weak oxidization of the sulphide minerals, believed to be due to the abundance of clay minerals resulting in poor permeability (Battle Mountain Canada Ltd., Tres Cruces Staff, 1999b).

Preliminary mine designs have been developed for mining oxide and transition mineralization for heap leach processing at the Tres Cruces Oxide Project. The designs and production schedule have been based upon Indicated and Inferred Mineral Resources. The resource model described in Section 14 was imported to Hexagon Mining - Mineplan 3D software where a Lerchs Grossmann algorithm was applied to an NSR model to determine possible pit limits.

The mine plan was developed to mine the oxide and transition mineralization from four phases. The assumed processing rate was nominally 6,000 t/d over seven years. The overall mining rate ramps up from 6 Mt/a to 9 Mt/a in Year 2 of the plan after two years of pre-production stripping. The total mine life is nine years with an overall life of mine strip ratio of 2.89:1.

The mine will be a conventional diesel equipment truck and excavator/wheel loader operation. Waste rock will be placed in a storage facility immediately south of the open pit. A small stockpile will be located immediately adjacent to the primary crusher and used as required to ensure a steady supply of mineralized material to the processing facility.

The Tres Cruces mine will be a conventional excavator/wheel loader operation using 50 t capacity offroad trucks. The bench height will be variable 5 m in mineralized material and 10 m in waste. Designs have been prepared for 10 m single bench between berms. Road allowances have been made for 25 m width. The pit will be 990 m long and 620 m wide with a total depth of approximately 130 m.

The main pit at Tres Cruces will be developed in 3 phases. The bottom bench elevation of this pit will be 4050 masl.

The Phase 2 pit will be developed to the northern limit of the main pit. A slot will be driven along the final northwest wall down to the pit bottom at 4035 bench.

The Phase 3 design will join the Phase 1 and Phase 2 pits removing oxide and transition resources to the base of the transition zone and leaving fresh rock in place. Access to Phase 3 will be a ramp located on the south and west walls of the final pit.

Waste rock will be placed in a storage facility located within the Anacortes property immediately south of the open pit and primary crusher. Waste rock will also be used for external road construction from the Phase 1 and Phase 3 exit point at 4110 m elevation up to the surface of the waste storage facility and across to the crusher and shop facilities. The waste storage facility will be constructed with final slopes of 2.5:1 H:V.

Drilling and Blasting
The resource model has been developed on a 5 m vertical block height. Mining will be carried out on a 5 m bench when mineral resources are available for processing. In areas that are predominantly waste drilling and blasting may be undertaken on a full 10 m bench with split bench excavation by backhoe configured machines or dozer/wheel loader combination. Production blast patterns will be implemented for 152 mm production holes with 114 mm wall control preshear lines. Overall emulsion powder factor of 0.22 kg/t has been assumed for oxide and transition material. Wet conditions are anticipated between October and March. Emulsion explosives will be delivered to the borehole by a contractor. Initiation of blast patterns will be undertaken by mine employees supervised by the engineering department.

Loading and Hauling
The loading fleet contemplated for Tres Cruces includes 2 diesel powered 6.5 m3 excavators, 1 - 11.6 m3 and 1 - 6.9 m3 wheel loaders. The excavators and 11.6 m3 loader will be the primary loading tools and the 6.9 m3 loader will be a back-up unit capable of loading trucks and tramming crusher feed from the stockpile to the crusher when required.

The larger wheel loader will be capable of loading 50 t off-road end dump trucks in three passes and have the flexibility to move between pit phases as required to meet overall production targets. The excavators will load 50 t trucks in six passes in mineralized material and waste and will allow selective mining at material contacts separating crusher feed and waste.

The truck fleet will initially be comprised of 6 units in pre-production working on short hauls to the waste dump from large near surface open benches. As additional phases of pit expansion are developed the fleet will increase to 11 units. Fleet availability is expected to commence at 92% with an assumption that this will decline approximately 1%/year/unit to a minimum of 86% over the life of mine.

Support Equipment
The support equipment fleet will include track dozers for road construction, waste dump maintenance, post blast cleanup, bench floor maintenance and other routine pit operations such as pushing to wheel loaders. Three track dozers have been included to cover multiple pit phases operating simultaneously and constant dump activity.

Provisions have also been made to include a grader, water truck, a ditching excavator, and a rock breaker. A low bed has been included in the fleet for moving drills and dozers between pit phases and a tire handler has been included for wheel loader and truck tires. A fuel truck and miscellaneous service vehicles have been included for the maintenance crew. A provision has been made for a small used portable crushing plant to produce road surfacing materials and crushed aggregate blasthole stemming.

The heap leach pad will also require a track dozer for leveling stacker placed crushed rock prior to leaching. A small loader may also be required for clean up around the crusher and stockpile areas. These will be included in the processing capital for mobile equipment.

Mine Dewatering
The Tres Cruces site is subject to a significant amount of precipitation on an annual basis with the rainy season occurring between October and March. Mine de-watering will be required by pumping from in-pit sumps and depressurization horizontal drain holes will be required on operating benches. Collected water will be pumped to the processing plant as make-up water.

Perimeter ditching will also be required to control surface contact water in and around waste dumps and pit perimeters. This topic is discussed further under site plan.

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The recovery process used at Tres Cruces will be a conventional three stage crushing circuit followed by heap leaching, and a carbon adsorption, desorption, regeneration (ADR) recovery plant. Pebble lime for pH control will be added to the crusher product and will be conveyor stacked on a heap leach pad in 8 m lifts.

Heap Conveying and Stacking.
The heap leach will be constructed in eight-metre lifts using a mobile conveyor stacking system. It is expected that the leach pad conveying and stacking system will consist of an overland conveyor, mobile grasshopper conveyors, and index feed conveyor, a horizontal index conveyor and a radial stacker. The overland conveyor transfers the material from the heap leach feed conveyor to the mobile grasshopper conveyors, which feed the conveyor stacking system. As the radial stacker progresses, the system is periodically stopped to add or remove grasshopper conveyors as needed. No additional equipment is expected to increase the l ........