The Breen Lake occurrence is located south of Breen Lake, approximately 500 metres west of Crofton Lake.

The area is underlain by east-northeast striking, steeply dipping andesitic and rhyolitic volcanics and volcaniclastics of the Upper Devonian McLaughlin Ridge Formation, Sicker Group. Large irregular gabbroic bodies (informally known as the Mount Hall Gabbro), coeval with the Upper Triassic Karmutsen Formation (Sicker Group), intrude the volcanics. Also intruding the stratigraphy are quartz-feldspar porphyry bodies of the Late Devonian Saltspring Intrusive Suite (formerly the Saltspring Intrusions).

Locally, as indicated by drilling, bands and beds of massive pyrite less than 0.4 metres thick are common. Sulphides including pyrrhotite also occur in chlorite-carbonate altered felsic lapilli tuff, andesitic tuff and quartz feldspar porphyry.

In 1969, Canpac Minerals explored the area as the Sirius claims. A program of geological mapping and a ground magnetic survey was completed. In 1978, the area was staked as the Croft 2 claim and a program of geological mapping and soil sampling was completed. In 1983, the area was staked as the West claims by R.J. Bilquist and a program of prospecting was completed. In 1984 and 1985, Falconbridge optioned the property and completed programs of geochemical sampling and an airborne geophysical survey.

In 1987, Falconbridge completed a drilling program of 10 holes, totalling 3170.7 metres. Drilling results are as follows:

- West87-20 intersected a 0.8 metre long sample of semi-massive pyrite-chalcopyrite in silicified mafic ash tuff that assayed 0.97 per cent copper. Another 1.0 metre section of strong pyrite mineralization assayed 0.64 per cent copper and 0.56 per cent zinc.

- West87-14 intersected a 1.2 metre section of semi-massive sulphides in chlorite-carbonate altered felsic lapilli tuff yielding 1.14 per cent zinc and 0.103 per cent copper. Another 0.15 metres section of massive pyrite-chalcopyrite assayed 2.08 per cent copper.

- West87-16 intersected a 0.12 metre sample of massive pyrite-chalcopyrite yielding 0.37 per cent copper. Another section of strongly chlorites quartz feldspar porphyry containing pyrite and chalcopyrite assayed 0.48 per cent copper over 0.7 metres.

- West87-03,04 encountered chalcopyrite mineralization in chlorite-carbonate altered andesitic tuff and yielded values of 0.31 to 0.34 per cent copper over 1.5 to 2.0 metres.

(Assessment Report 17007)

In 2010, Westridge Resources completed a program of geological mapping and geochemical sampling on the Breen Lake area.