Porcher Island Mine is located in the Refuge Bay area on North Porcher Island, approximately 37 kilometres south-southwest (209°) of Prince Rupert.

A quartz diorite stock of the Tertiary-Jurassic Coast Plutonic Complex intrudes Paleozoic-Mesozoic metasediments and metavolcanics. The stock is about 2.8 kilometres in diameter, with a 300-metre wide outer hornblende quartz diorite phase and a quartz diorite core. The metamorphosed rocks consist of chlorite schist and grey metasediments striking northwest and dipping moderately northeast. All rocks are intruded by mafic dikes.

Early exploration of Porcher Island began in 1916. Records show that mining from 1919 to 1939 resulted in 61,567 tonnes of ore yielding 639,914 grams of gold, 225,994 tonnes of silver and 4161 kilograms of copper from the Surf Point and the Edye Pass mines (103J 015), located 500 metres to the north. The mines produced ore from near-surface workings between 1919 and 1939, when Reward Mining Company built a 50 ton-per-day mill to replace a smaller structure that burnt down the previous year. The operation probably closed as a result of staff shortages induced by the war. The Surf Point mine operated between 1934 and 1937 (inclusive) and the Edye Pass mine operated from 1919 to 1939.

The ore came from numerous, steeply dipping, shear-controlled quartz-pyrite-gold "ladder veins" that formed near the apical tip of a composite flow-banded quartz diorite pluton intruded into schist during Tertiary uplift and deformation. The veins are short, narrow and hard to project with any degree of certainty, so continuity can be a problem. There is almost no wallrock alteration and the veins are tightly bonded to the diorite. The deposit is very similar to Harrison Gold (092HSW092).

The short and irregularly distributed veins or lenses of auriferous pyrite and chalcopyrite in quartz veins occur largely within the quartz diorite. Small amounts of sericite, ankerite, calcite and chlorite can be observed in the veins. Under the microscope, tetradymite may be seen accompanied by free gold. The veins strike 070 to 090 degrees, dip 60 to 90 degrees north and seldom exceed 120 metres length. Widths average 30 centimetres and seldom exceed 1 metre.

The deposit lies in a 300 by 200 by 30 metre zone along an arch of flow layers with an axial plane that strikes about 020 degrees and dips about 85 degrees southeast. A primary joint system in the stock is related to the orientation (030 degree trend, 50 degree plunge) of flow lines which lie within the plane of the flow layers. The ore-bearing solutions entered soon after the formation of the fractures. A northeast trending shear zone forms the southern limit of the deposit.

Work on the deposit by Cathedral Gold Corporation has resulted in the discovery of the AT zone, about 50 metres west of Adit No. 4 portal. Mineralization is persistent to a depth of 550 metres and remains open. The zone also remains open along strike. Based on 66 holes, totalling 12,192 metres, the AT zone contains 544,300 tonnes of indicated reserves grading 6.86 grams per tonne gold, plus an additional 816,500 tonnes of inferred reserves at the same grade (Northern Miner - April 21, 1997).

Proven and probable reserves are estimated at 300,000 tonnes grading 7.8 grams per tonne gold; possible reserves are estimated at 190,000 tonnes grading 7.8 grams per tonne gold; and further possible deep reserves are estimated at 800,000 tonnes grading 6.9 grams per tonne gold. Included in these reserves are 82,000 tonnes of direct-shipping ore grading 13.7 grams per tonne gold, all accessible above the existing mine levels (Information Circular 1995-1, page 14).

Between 1975 and 1994 several mining companies, including Tombil Mines, Banwan Gold Mines and Cathedral Gold Corporation conducted exploration and developmental work on the Porcher Island gold mine property. From 1975 to 1988, extensive exploration by E & B Explorations Inc. and Cathedral Gold Corporation resulted in a drill outlined mining resource. A deep drilling program indicated the potential for additional tonnages to a depth of 305 metres below surface in the AT zone.

The past-producing Surf Point/Edye Pass mines on Porcher Island is presently (August 2000) owned by Cathedral Gold Corp. and was, until recently, under option to Tetra Metals Ltd., who were unable to attract the financing.

In 2005, Cross Lake Minerals Ltd. entered into an option agreement to earn a 65 per cent working interest in the Porcher Island gold property from Imperial Metals Corporation. Cross Lake commenced a surface diamond drilling program to extend the area of known mineralization at the northern end of the AT zone. Drilling in December 2005 totalled 571.9 metres of NQ2 core size in three holes to verify gold mineralization identified by previous operators on the eastern side of the AT zone.

In 2015, Imperial Metals Corp. conducted an exploration program to locate old showings on their Porcher Island property. The program included 9 rock samples from showings, 32 soil samples and 12 stream sediment samples. The highest rock sample sample #780401 with 45g/t Au gold over a 45 centimetre width was located 60 m west of the drill pad where earlier exploration was conducted on the Cedar Vein system 200 m east of the historic Dawson workings in the area of the lineament of the Edye Shear zone. This location is approximately 400 metres northwest of the Porcher Island Mine. The stream sediment sampling proved successful in delineating the Edye Shear, a known gold bearing area, as a gold target (Assessment Report 35801).