The Renfrew occurrence is on the east bank of Siwash Creek, 2.4 kilometres north of the creek's confluence with Tepee Creek and 38 kilometres north-northeast of Princeton.

This prospect is hosted in a stock of quartz porphyritic monzonite, granite and quartz syenite, intruding granite of the Middle Jurassic Osprey Lake batholith. This stock is one of a series of small granitic bodies of early Tertiary age referred to as the Otter intrusions. It is strongly altered to a soft watery green to buff rock, possibly the product of kaolinite-sericite alteration. Silicification accompanies this alteration in areas of shearing.

A quartz vein, 15 to 35 centimetres wide, strikes 041 to 089 degrees and dips 45 to 55 degrees southeast. The vein has been traced downdip for 72 metres and along strike for 140 metres in three levels of adits spaced over a vertical elevation of 50 metres. A black fine grained basaltic dike follows the footwall of the faulted vein in the upper two adits.

Mineralization consists of galena, pyrite, argentite, tetrahedrite and arsenopyrite. Realgar forms small segregations in sheared granite near the vein. A sample taken across the vein in the uppermost tunnel assayed 3.4 grams per tonne gold and 9250 grams per tonne silver (Minister of Mines Annual Report 1917, page 206).

Various shear zones, several centimetres to 1.5 metres wide, and striking northeast, occur in the vicinity of the vein. Quartz veins are commonly developed along the shears. These veins and areas of silicification are mineralized with pyrite, sphalerite, galena, chalcopyrite and arsenopyrite.

Three adits totalling 119 metres in length, were excavated in 1916 and 1917. In 1926, 24.5 tonnes of ore grading 3.81 grams per tonne gold, 4291 grams per tonne silver and 2.92 per cent lead were mined and shipped to the smelter in Trail (Minister of Mines Annual Report 1927, page 247). Recent work in the area by various operators, including Brenda Mines Ltd. (1979-1981), Tower Hill Mines Ltd. (1988) and Inel Resources Ltd. (1989), appears to have failed to relocate this occurrence. (Note: this prospect is not to be confused with the Snowstorm showing to the south (092HNE032), whose underground workings have been relocated).

The area has been explored in conjunction with the nearby Snowstorm (MINFILE 092HNE032) occurrence and completed exploration history can be found there.