The Fosselli Creek Road occurrence is located on the Fosselli Creek Road approximately 2.6 kilometres south of the creek mouth, at an elevation of 650 metres. The occurrence is 9 kilometres west of Port Alberni.

The area is underlain by a narrow band of limestone of the Upper Triassic Quatsino Formation (Vancouver Group) which strikes northwest under a saddle, between Karmutsen Formation (Vancouver Group) andesite on the northeast and Bonanza Group volcanics on the southwest. A few exposures of Parson Bay (Vancouver Group) sedimentary rocks occur between the Quatsino and Bonanza rocks. Dioritic to granodioritic intrusions of the Jurassic Island Intrusions are exposed to the north and east.

Locally, a 30 centimetre shear zone, striking 220 degrees and dipping 80 degrees northwest, hosts semi-massive pyrite and chalcopyrite.

In 1989 and 1990, Simplon Resources completed a program of rock sampling and geological mapping on the Foss 1-2 claims. A select chip sample of the sulphide band assayed 1.4 per cent copper and 0.26 gram per tonne gold (Assessment Report 20303).

In 1996 through 2006, SYMC resources prospected the area as part of the Macktush property along the west side of the Alberni Inlet, now called the Dauntless property. In 2009 through 2011, G4G Resources completed programs of geological mapping and rock and soil sampling on the area as the Macktush Copper property. In 2012, Nahminto Resources completed a satellite remote sensing survey and analysis on the Macktush group and continued programs of prospecting, geological mapping and rock sampling from 2012 through 2014. A similar prospecting, geological mapping and rock sampling program was conducted on areas of the Macktush property for World Organics Inc. in 2015.