The McKinley mine is located on Crown granted Lot 140s, located approximately 2.7 kilometres south-southwest of Mount Franklin.
The area is underlain by volcaniclastic and sedimentary rocks of the Carboniferous to Permian Harper Ranch Group, which have been intruded by granite and granodiorite of an un-named Middle Jurassic Intrusion. These are overlain by undivided volcanic rocks of the Eocene Penticton Group. A rhyolite porphyry caps Mount McKinley and overlies the Harper Ranch Group to the southeast.
The occurrence is located in a north-south striking skarn zone along the contact between two marble lenses, an altered tuff of the Devonian-Triassic Harper Ranch Group and an east-west– striking silicified pyritic porphyry. The porphyry varies from 90 to 105 metres wide, while the two limestone beds are 54 and 30 metres wide. Granodiorite of the unnamed Middle Jurassic intrusion is found in the vicinity of the ore zones and forms a large mass approximately 500 metres to the north west.
Mineralization consists of chalcopyrite, galena and sphalerite, with pyrite and magnetite, in a gangue of garnet, epidote, tremolite, diopside, quartz, chlorite and calcite. Three types of sulphide mineralization have been recognized: pyrite-chalcopyrite, galena-sphalerite, and magnetite-pyrite. Massive pyrite-chalcopyrite ore is found in the skarn zones, although disseminated pyrite is also found in the altered tuff. Galena and sphalerite are found as disseminations and small masses associated with the carbonate-rich areas. Magnetite with pyrite forms a massive band along the east border of the lower marble lens, and is also found disseminated in garnet-rich skarn. Azurite, malachite and limonite are found in surface exposures.
The McKinley claim was located by J. Wilcher in 1896 and Crown granted as Lot 140s to McKinley Mines in 1906. Work during the early 1900s consisted of extensive stripping, the excavation of numerous trenches and open cuts, diamond drilling and the underground development of at least four adits. In 1904, a glory hole, measuring approximately 25 metres long by 12 metres wide by 9 metres deep, was blasted in ore that averaged 3.5 per cent copper and $2.50 in gold and silver (Minister of Mines Annual Report 1904, page 223). Approximately 75 metres to the southeast, an open cut, measuring 9 metres long by 6 metres wide and 7.6 metres deep, was made in ore that averaged 4.5 per cent copper and $2.00 in gold and silver (Minister of Mines Annual Report 1904, page 223). A shaft was sunk from the open cut and a cross-cut was driven for 16 metres from the bottom of the shaft. Approximately 50 trenches were also noted on the property in 1904. By 1905, the tunnel had been extended to 66 metres, 34 metres of which were in ore. In 1906, two diamond drills on the property were "testing and sampling the ore deposits in every direction" (Minister of Mines Annual Report 1906, page 163). In 1915, it was noted that a total of 121 metres of tunnels existed on the McKinley property. The No.1, 2 and 3 tunnels are located at elevations of approximately 1058, 1020 and 1028 metres, respectively.
In 1948, the mine was rehabilitated by W.E. McArthur. Some stripping was carried out on the property and approximately 36 tonnes of ore were hand-sorted for shipping in 1949.
In 1949, approximately 96 tonnes of ore were mined and shipped to Trail for smelting. A total of 132 tonnes of ore were shipped, yielding 28,397 grams of silver, 14,737 kilograms of lead and 22,523 kilograms of zinc (Minister of Mines Annual Report Index 3, page 204). It is also reported that the shipment contained 62 grams of gold and averaged 3 per cent copper (Minister of Mines Annual Report 1949, page 155). Diamond drilling in 1949 failed to find any more ore.
In 1969, a program of rock, soil and silt sampling, geophysical surveys, geological mapping and trenching was completed. The No.1 adit was also re-opened at this time to allow underground mapping and sampling. Three surface samples yielded 1.05, 0.63 and 0.21 per cent copper over 3 metres, respectively (Property File - R.W. Phendler [1970-06-19]: Report on the Franklin Camp Grand Forks, British Columbia for Great Plains Development Co. of Canada Ltd.).
In 1970, Great Plains Development Co. completed a program of geological mapping and sampling. A chip sample (38255) from the east end of the western skarn zone assayed 1.28 per cent copper and 28.0 grams per tonne silver over 4.5 metres (Property File - R.W. Phendler [1970-06-19]: Report on the Franklin Camp Grand Forks, British Columbia for Great Plains Development Co. of Canada Ltd.).
In 1986, Longreach Resources acquired a large number of claims in the area, including the McKinley occurrence. A program of geophysics and diamond drilling, totalling 1868 metres, was performed. The property was then optioned to Placer Dome, who completed a detailed mapping and sampling program and electromagnetic surveys.
In 1989, a rock sample (BCS 18402) of siliceous skarn assayed 0.17 gram per tonne gold, 62.5 grams per tonne silver and 5.64 per cent copper (Property File - Lee, L. [1989-11-01]: Summary Report - Burrell Creek).