Wheaton Precious Metals Corp.

Sampling, Analysis and Data Verification

RC and core drill holes were sampled at intervals of 2 m. Bulk density values were collected primarily using the water immersion method.

Independent laboratories used for sample preparation and analysis included ALS Chemex, and Bondar Clegg (absorbed into ALS Chemex in 2001). At the time the early work was performed ALS Chemex was ISO-9000 accredited for analysis; the laboratory is currently ISO-17025 certified. Independent check laboratories included Acme Laboratories in Vancouver, which at the time held ISO-9000 accreditation, and more recently, SGS Mexico (SGS), which holds ISO/IEC 17025:2005 certification. Theon-site mine laboratory is not certified and is not independent of Newmont.

Various sample preparation crushing and pulverizing protocols were used since the late 1900s, depending on the drill campaign. ALS Chemex crushed to either ≥70% or 75% passing 10 mesh (2.0 mm) and pulverized to either ≥85% or ≥95% passing 200 mesh (75 µm). The onsite laboratory crushed to ≥70% passing 10 mesh and pulverized to ≥85% passing 200 mesh (75 µm). Analytical methods also varied by campaign. Gold analyses consisted of fire assays with either atomic absorption (AA) or inductively-coupled plasma (ICP) emissions spectrometer (ES) finishes. Overlimits were assayed using fire assay with a gravimetric finish. Silver assays were performed using ICP-ES or ICP atomic emission spectroscopy (AES). Overlimits were assayed using fire assay with a gravimetric finish. Zinc and lead assays were reported from either ICP-AES or ICP mass spectrometer (MS) methods.