The Whitehorse Copper Belt is located west of Whitehorse and contains 30+ mines, deposits and showings. By 1900, most of the important deposits had been discovered and the first small ore shipment was made that year. Many of the occurrences in the Copper Belt are skarns. The skarns form on or near the contact between the Whitehorse batholith and the Lewes River group. The Whitehorse batholith is commonly a grey coarse-grained hornblende granite and ranges from quartz monzonite to granodiorite to diorite. The Lewes River group contains numerous different rock types, most importantly of which is the limestone group, which is essential in the formation of skarns in the area.  A small number of occurrences within the Copper Belt are vein and/or replacement and occur within the Whitehorse batholith granite.

The Copper King deposit occurs in an irregular shaped roof pendant of limestone (Lewes River group) and skarn, about 600 feet in diameter and is enclosed in the north, east and south by a hornblende rich granite (Whitehorse batholith). The contact is marked by a strong alteration from limestone to brown garnet and epidote. Mineralization is in the form of bornite and chalcopyrite.

Assays for the copper ore at the Copper King 0.01 oz. per ton and 3.58% Cu. Production between 1900 to 1908 was 453 tonnes of ore at 15% Cu and 68.57 g/t Ag and production between 1915 and 1920 was 2 982 tonnes at 10% Cu.