Both the Eagle River and Mishi deposits are mesothermal lode gold deposits hosted by Archean Greenstone Belts.

In the Mishi Mine area mineralization is hosted by a series of at least 8 tabular parallel zones consisting of ankerite-sericite ± chlorite alteration zones containing 2-8% fine disseminated and a system of sub conformable, dislocated, smoky grey quartz veinlets and lenses. Veins generally vary from 5-20% of the bulk volume of the zones with individual quartz lenses commonly 5-15 centimetres wide.

The 8 zones recognized to date are labelled from south (footwall) to north (hangingwall) M2, M4, M6, M8, M10, M12, M14 and M16. Zones M2 and M4 are close together and are merged when modelling into a Main Zone. The zones strike 100º, dip north 40º and plunge northeast. In general the zones become more felsic, discrete and vein dominated towards the north. Additionally, they appear to be converging eastward and possibly diverging westward.

The Mishi Pit deposit has been designed as an open pit with a planned ore production rate of 160,000 tonnes per year. The mining rate will supplement the 150,000-160,000 tonnes per year currently planned for the underground Eagle River Mine in order to feed the Eagle River Mill, which has a capacity of 320,000 tonnes per year.

Mining will be undertaken by mining contractors using conventional truck and shovel equipment. The selected equipment is a 40-tonne capacity range truck and an excavator of appropriate size for ore and waste assuming a bench height of 5 m. However, the ramp will be located on the footwall side.

Present mining utilizes a surface fleet of equipment consisting of up to four production drills producing 2.5 inch to 3 inch diameter blast holes, up to five 50 tonne haulage trucks, up to three excavators, a dozer and surface utility vehicles on single shifts during the day.

Wesdome initially leased then subsequently acquired the former Magnacon mill and tailings facilities in 1996. The mill is 17 kilometres by road from the mine. The mill capacity was increased from 600 to 1,000 tonnes per day in 1999. Even though the addition of the cone crusher expanded capacity to the permitted level of 1,200 tonnes per day on a crushing basis, required maintenance time means the practical limit is approximately 1,050 tonnes per day as it is configured to achieve targeted gold recoveries.

The mill employs the Merrill-Crowe process for the recovery of gold from Eagle River ore with about 40% of the gold recovered into a gravity concentrate using a Knelson concentrator. The Merrill-Crowe process involves cyanide solution and zinc precipitation. Precipitate is refined on site to produce doré bars containing approximately 80%-92% gold. By-product silver is recovered at a rate of one part for every six to ten parts of gold. The doré bars are shipped to the Royal Canadian Mint in Ottawa for refining. Overall mill recoveries for Eagle River is around 95% and for Mishi ore around 87%.

The mill tailings commonly averages grades of 0.25-0.50 g/t are deposited in the tailings pond. Water from this pond is reclaimed for use in the mill process as required to minimize the discharge of effluent. The mill operates 24 hours per day, seven days per week with two crews working 12 hour shifts on a seven days in, seven days out rotation.