The Sleeper deposit is located on the western foothills of the Sleeper range, in NW Nevada. It consists of an epithermal Au-Ag vein system controlled by an extension-related system of NW, NS and bed-parallel structures affecting stratified rocks.

Bed parallel structures related to the base of the rhyolite porphyry and the contact also act as control for Lower grade, disseminated mineralization.

NW structures act as discontinuities for the main N-S veins, as well as hosts for lower grade mineralization.

Four main types of gold mineralization are found within the Sleeper deposit and may represent a continuum as the system evolved from a high level, high sulphidation system dominated by intrusion related fluids and volatiles to a low sulphidation meteoric water dominant system (Corbett, 2005, Utterback, 2005, Histed, 2005). In this setting the paragenetic relationships of the differing mineralization styles are as follows:
* Early - quartz-pyrite-marcasite stockwork
* Intermediate - medium-grade, silica-pyrite marcasite cemented breccias localized on zones of structural weakness
* Late - high-grade, banded, quartz-adularia-electrum-(sericite) veins
* Post - alluvial gold-silver deposits in Pliocene gravels.

The mining operation was assumed to employ conventional surface mining methods, with drill and blastrock breakage and truck and loader materials handling.

The block model used 10x10x10 meter blocks. This is considered a reasonable basis for selection at the anticipated mining rates for the project. The average grade of each block was considered to have captured mining dilution. For the mining selection process, blocks were labeled for 4 material types; (1) Facilities Zone material (an area on the eastern edge of the Sleeper surface mine excavation), (2) Sleeper Zone material (low grade continuation of the original Sleeper deposit at depth), (3) West Wood and (4) Mine Dumps and Alluvial material from historic Sleeper mining operations. Within each of the zones, each block was labeled as either oxide or unoxidized.

Pit optimization results from an evaluation of each block based on projected costs, grade and metallurgical recovery. The parameters used in the optimization process are listed in Table 16.1. Other cost account for dewatering, and were applied to blocks below the current water elevation of 1248 meters. A preliminary geotechnical evaluation has been performed for Sleeper surface mining to provide a basis for pit slope recommendations (Kinakin, 2012). A range of preliminary inter-ramp slope angle recommendations was developed based on mining surfaces projected for expansion of the mine excavation, and classified as “conservative”, “base” and “aggressive”. The “base” recommendation of 45 degrees was used in the PEA Whittle analysis. Further refinement of the pit slope recommendations would be performed for more advanced engineering studies, after the mining surface has been defined.

The process facilities in the PEA were assumed to be standard cyanide heap leaching with carbon-in-column and ADR recovery plant. Heap leach material would be crushed to P80-3/4 inch (19 mm) using a primary and secondary crushing circuit. It was assumed that agglomeration would be required for the heap leach. For the heap leach only system, the crushing circuit would be sized for 30 ktpd throughput, with a stockpile of mineralized material developed to level the process rate.

The process facilities would produce a dore’ for direct sale to a regional refinery.