The Kathryn occurrence is located in the upper western head waters of a of a north facing creek gully in the eastern head waters of Raffuse Creek, at an elevation of approximately 1230 metres.

The area is underlain by a roof pendant of rhyolitic and andesitic tuff and agglomerate of the Lower Cretaceous Gambier Group. The volcanic rocks overlie Late Jurassic leucocratic granodiorite of the Jurassic to Tertiary Coast Plutonic Complex. The elongate, keel shaped, roof pendant trends west-northwest for 2 kilometres and is up to 1 kilometre wide.

Locally, sheared and oxidized rhyodacites and pyritic andesitic volcanic rocks host quartz veins with pyrite, chalcopyrite, sphalerite and galena mineralization.

In 1981, a 3.0 metre rock chip sample (No.43) assayed 0.42 per cent copper, 0.16 per cent zinc and 4.9 grams per tonne silver, while a rock sample (No. 79) assayed 0.38 per cent lead and 0.74 per cent zinc (Assessment Report 09714). The following year, a rock sample (E225) assayed 0.26 per cent copper, 0.47 per cent zinc and 2.9 grams per tonne silver (Assessment Report 11052)

During 1980 through 1982, Alpen Exploration completed programs of rock, soil and silt sampling, prospecting and a ground magnetometer survey on the area as the Kathryn, Sarah and Diddi claims. During 2005 through 2015, the area was prospected as the Mamquam 1-5 claims.