The Copper Cliff occurrence is located on the western side of Quadra Island near Gowland Bay.

The first recorded mining on the western side of Quadra Island was in 1906 and 1907, when high-grade cores from the Copper Cliff occurrence were mined from an adit in the cliff face and shipped to a smelter in Ladysmith. Between 1915 and 1919, ore from the Pomeroy area (092K 071,072,119) was mined by the Valdez Copper Company and shipped to the smelter at Anyox. Samples from the Senator claim (092K 052) in the Pomeroy area were tested for radium in 1922. In 1929, Hercules Consolidated Mining Smelting and Power Company acquired the Pomeroy area as the Hercules 1 to 10 claims. In 1930, carnotite was identified from a sample from the property, however, its presence was not confirmed by other investigators. Between 1952 and 1953, Dodge Copper Mines drilled 145 drillholes totalling 2682 metres on various properties. In 1964, mining was conducted from a shallow pit on the Beaver occurrence (092K 073). Lonrho Explorations mined and heap leached ore from the Pomeroy 1 (092K 072) occurrence in 1968 and 1969. Between 1970 and 1979 portions of the area were held by Western Mines, Prince Stewart Mines, Quadra Mining and Quadra Bell Mining. During this period the Copper Bell occurrence (092K 105) was discovered by E.P. Sheppard. In 1990, G.M. Ford identified the area as containing significant copper reserves that may not have been adequately explored and staked the CCT, MCT and BN claims. They were subsequently optioned to Mintek Resources Ltd. who conducted a photometric analysis of the claim area.

The Copper Cliff occurrence was first explored in 1919 when a small adit was driven on high grade copper mineralization. The first extensive exploration program was carried out in 1952-53 by Dodge Copper Mines and included 2682 metres of diamond drilling in 145 holes. An ore shipment was made to the Britannia mill in 1963. Quadra Mining Company Ltd. produced copper from an in situ bioleaching test in 1968 from the Pomeroy zones (092K 071,072). A mine permit was granted in 1973 but low copper prices and unfavourable political climate prevented commencement of production.

The western-half of Quadra Island is underlain primarily by andesitic volcanic rocks of the Upper Triassic Karmutsen Formation which are overlain and bounded on the east by a northwest trending belt of Upper Triassic Quatsino Formation limestone, both of the Vancouver Group. The area is underlain by Tertiary volcanic rocks of the Calden series that dip gently to the southeast. The amygdaloidal andesitic to basaltic flows range in thickness from 0.30 to 3.65 metres interlayered with dense, fine to medium grained andesitic units and minor thin beds of sedimentary and tuffaceous material. The amygdules are filled with calcite, quartz, chlorite, actinolite or prehnite. The rocks are chloritized and cut by numerous stringers and veinlets of quartz, calcite and epidote.

Chalcocite is the most abundant mineral with native copper and chalcopyrite in lesser amounts. Bornite and pyrite are rare. Malachite, azurite and cuprite are confined to oxidized and weathered surfaces. The distribution of the mineralization is erratic. It is found along fracture plane surfaces and within irregular quartz- calcite veinlets, less commonly it occurs within amygdules or is otherwise locally disseminated. The mineralization tends to be more concentrated where fracture density is high.

The Copper Cliff is comprised of chalcocite mineralization within fractured amygdaloidal andesite flows. The chalcocite is predominant within the amygdules but is also irregularly distributed throughout the flow. Chalcocite and occasional native copper also occur along fracture planes. The flows strike 140 degrees and dip 30 degrees southwest. A flat lying conformable mineralized horizon up to 2.1 metres thick has been previously mined out. An extensive malachite halo has been developed for 274 metres along a cliff face.

In 1973, reserves of 272,130 tonnes at 3.05 per cent copper have been classified as inferred ore (Sheppard, 1973).

A shipment of 323.86 tonnes was made in 1963 which ran 1.63 per cent copper (Assessment Report 19282).