The Som showing is located between Cayuse and Little Cayuse Creeks, on the northwestern shore of Lower Arrow Lake.
The area is underlain by an unnamed Jurassic pluton just to the west of its contact with Mount Roberts formation a sequence of Pennsylvanian Permian sediments. Intrusive dikes ranging in composition from lamprophyre to syenite cut the granite on the property and generally strike steeply northwest or northeast.
Locally, several erratically developed zones of milled granite with hematite/magnetite on fractures and some disseminated pyrite occur along with two parallel- trending syenite dikes 2 to 4 metres in width. The strike of the dikes was approximately 350° with near- vertical dips.
Quartz veining occurs in the granodiorite as single quartz veinlets to more well developed sheeted stockwork type zones. The veins range in width from hairline fractures with quartz coatings to individual veins over 15 centimetres wide, with 1 to 2 centimetres wide being the most abundant. Limonite and pyrite as well as chalcopyrite and molybdenite were noted within the veins. Alteration consists of chlorite, carbonate, epidote and garnet with sericite.
Disseminated pyrite and rare molybdenite occurs along the margins of the veins, often over thicknesses 3 to 4 times the width of the accompanying vein. Some of the vein margins also displayed a banded mylonitic texture, especially in the areas of more closely spaced stock-work -style veining. The strike of the veining was generally to the northeast varying from 20 to 45 degrees with moderate dips to the northwest.
In 2005, five rock samples were collected returning values up to 255 parts per billion gold, 27 grams per tonne silver and anomalous values in copper, bismuth and molybdenum (Assessment Report 27843).