The Patriarche occurrence is located below the railway tunnel on the western side of Finlayson Arm, across from Sawluctus Island.

The area is underlain by rocks of the Triassic to Cretaceous Leech River Complex (Formation), Chert-Argillite- Volcanic Unit. This package comprises ribbon chert, cherty argillite, metarhyolite, metabasalt and chlorite schist. On the property the rocks are reported to be slates, greywacke and schists interbedded with andesitic volcanics. The rock contains areas of graphitic material and quartz injections that occur along flat-lying fractures. The general trend of the formation is east-west, with schistosity and fractures dipping near vertical. The horizontal fractures appear to be of later origin.

Mineralization noted in the volcanics consists of pyrrhotite, minor magnetite, some manganese staining and very minor chalcopyrite.

In the 1967, C.P.O & G. Ltd. completed a program of soil sampling and a self potential geophysical survey. A bulked grab sample taken over 2.4 metres assayed 0.16 per cent lead, 0.015 per cent copper, 0.012 per cent zinc and 0.02 per cent tin (Patriarche, 1967). Considerable amounts of pyrrhotite and carbon or graphite were present in this sample section.

In 1986 through 1988, Redwood Resources completed programs of prospecting, rocks sampling and geological mapping on the Tunnel Hill claims. A sample (6681) assayed 0.0175 per cent copper, 0.0353 per cent zinc and 1.4 grams per tonne silver. Other samples assayed up to 0.14 grams per tonne gold (Assessment Report 15088).