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 Keewenaw deposit is an oval-shaped zone about 500 feet (152 m) long and 250 feet (76 m) wide. The zone trends southeasterly and there are numerous dark, fine-grained diorite dykes (< 10 - 30 ft. wide, < 3 - 9 m wide) which cut the granite at a southeast trend. The granite is cut by felsite dykes and by feldspar porphyry dykes that also strike southeasterly. The oval shaped zone contains bornite and malachite and the fine-grained granite is strongly altered to epidote and chlorite with numerous fine-grained veinlets and fractures. The silicate chrysocolla is present in some rock cuts. Sheared granite zones contain bornite and occasional malachite.

Production during 1971 totalled 151 770 tonnes of ore at 1.02% and produced 1 596 tonnes of refined metal at 99% Cu. Calculated reserves at the end of 1971 totalled 202 653 tonnes of ore at 1.06 Cu.