The Thunder occurrence is located on the Cypre River, approximately 1 kilometre north of the river mouth, and 15 kilometres north of Tofino, B.C.

The area is underlain predominantly by a northwest trending sequence of mafic volcanics and sediments of the Paleozoic Sicker Group. These rocks are intruded by Paleozoic or Triassic diabasic sills and feldspar porphyritic dykes of possible Tertiary age. In gradational contact are gneisses, hornfelsic basalts and amphibolites of the pre-Jurassic Westcoast Complex.

A grab sample taken on the east bank of the Cypre River, on the Cats Eye 4 ckaim, from a 6-metre-wide shear fracture zone, assayed 1.90 per cent copper, 3.43 grams per tonne silver and trace gold (Assessment Report 3443).

Across the river to the west, on the Cats Eye 5 claim, disseminated chalcopyrite is reported to occur in meta-andesite and gabbro. A sample of this material assayed 0.25 per cent copper over 4.6 metres (Assessment Report 3443).

Chalcopyrite is also reported to occur in stringers at this location. Rocks are described as diabase (Assessment Report 17098).

In 1970 and 1971, Thunder Valley Mines completed programs of geological mapping, silt and soil sampling and ground and airborne geophysical surveys on the area as the Cats Eye and Hot claims. In 1972 and 1973, Texada Mines completed programs of geochemical sampling and geological mapping on the area as the Cypress and Top claims. In 1987, Suntac Minerals completed a program of rock and soil sampling and a ground electromagnetic survey on the area as the Good Friday claims. In 2010, 2011 and 2012, Catface Copper Mines Limited completed programs of rock, silt and soil sampling on their large Catface NE property on the Bedingfield Peninsula.