The Nimpkish Copper (Campbell Creek/Allan Creek) occurrence is located on the southeast side of Tolnay Creek, a tributary of Sutton Creek at an elevation of 713 metres. The showing is situated approximately 28 kilometres northwest of the town of Gold River.
The area is underlain by Upper Triassic Vancouver Group Karmutsen Formation pillow lavas with minor interbedded limestone which have been intruded by granodiorite of the Jurassic Island Plutonic Suite.
Locally, an assemblage of limestone, argillites and volcanics in contact with intrusive rocks, is skarned over 104 metres. A strong northwest fault cuts diagonally across the skarn and localizes massive chalcopyrite with pods of chalcocite and bornite. The fault may be parallel to the intrusive contact. It strikes 160 degrees and dips steeply to the east. The sulphide zone ranges in width from 0.35 to 1.5 metres, averaging 0.46 metres over its 7.6 metre exposure (Assessment Report 728).
2013 prospecting on the Preston property showed that chalcopyrite was found to be associated with K-feldspar, epidote ± garnet and amphiboles. The mineralization is spatially related to the contact metamorphism and metasomatism of the Karmutsen and Buttle Lake groups by the Island Plutonic Suite. Chalcopyrite is not confined to the skarnified limestone. In the north of the property the chalcopyrite is found as clots within the thick units of basaltic volcanic rock.
In 1972, an assay of 30.03 per cent copper was obtained over 1.1 metres (Assessment Report 4102). In 2011, a sample (110806-1) assayed 30.32 per cent copper, 0.379 per cent zinc and 112.6 grams per tonne silver (Assessment Report 33027).
In 1965, Empire Development completed a program of prospecting and geological mapping on the area as a part of the Nimpkish Copper property. In 1972, First National Mines completed a program of geological mapping and rock sampling on the area as the HK 1-2 claims. In 1990, the area was prospected as the Maybee A claim. In 1993, Noranda completed a program of airborne geophysical surveys on the area as a part of the Muchalat property. In 1995 and 1996 the Campbell Creek area was prospected, stream sampled and rock sampled by Westmin Resources Limited, operating for Doromin Resources Ltd., as part of the Dragon property.
In 1996, R.J. Lightle prospected the area. In 2011, the area was prospected as part of the Preston property. In 2012 and 2013, Santa Fe Metals Corp., on behalf of British Pacific Minerals Ltd., carried out programs of prospecting, stream sediment and rock sampling on the Preston property. The sampling of mostly metasedimentary rocks returned anomalous values of copper (ranging between 0.0002 and >1 per cent) and silver (ranging between <0.1 to 3.3 grams per tonne). The sampling was followed up by a small microdrill program, totalling 13.7 metres, to determine the extent, style and potential of copper, silver, zinc, lead mineralization at the massive sulphide lens in Campbell Creek. Channel drilling confirmed that the massive sulphide lens extends along strike length beneath the overlying marble for an additional five metres from surface and is open along strike in a northwest direction.
