The Dorreen gold mine is located 20.8 kilometres north of the Cordillera mine site (103I 040) and is situated on Knauss Mountain, 6 kilometres west of the Canadian National railroad and the Skeena River, about 35 kilometres north-northeast of Terrace.
The area is underlain by Lower Jurassic volcanics of the Hazelton Group and Upper Jurassic sediments of the Bowser Lake Group. The strata are comprised of laminated argillites, bedded tuffs and interbedded andesite flows. The rocks strike 130 degrees and dip 25 degrees northeast and are intruded by a 45-metre wide quartz diorite dike, which strikes 150 degrees and dips 55 degrees southwest.
The Fiddler quartz vein occurs along a bedding fault plane in argillite, below an andesite bed and near the intrusion. The lens-shaped vein has been traced for 100 metres and is up to 1.7 metres wide. A 30-centimetre channel sample assayed 33.6 grams per tonne gold, 161.8 grams per tonne silver, 6.73 per cent lead, 3 per cent zinc and 1.04 per cent copper (Geological Survey of Canada Memoir 212). Mineralization consists of chalcopyrite, covellite, galena, pyrite, sphalerite, tetrahedrite and arsenopyrite.
A smaller vein assaying 32.2 grams per tonne gold, 19.2 grams per tonne silver, 1.28 per cent lead and 0.24 per cent copper over 0.2 metre occurs 21 metres stratigraphically above the main vein (Geological Survey of Canada Memoir 212).
In 1912, the Dorreen gold vein was discovered and developed intermittently from 1914 to 1952. Three ore shipments were made; in 1924, 1926 and 1952. In 1924, 80 tonnes of ore was shipped and reportedly assayed 57.26 grams per tonne gold, 205.71 grams per tonne silver, 1.3 per cent copper, 6.2 per cent lead and 5.8 per cent zinc. In 1926, approximately 8 tonnes of similar ore was shipped. In 1952, 476 tonnes of ore was shipped and 3266 grams of gold, 8118 grams of silver, 3137 kilograms of lead and 1342 kilograms of zinc were recovered. No further development has occurred since 1952.
In 1981, Canamco Resources completed a program of airborne geophysical surveys, totalling 206 line-kilometres, on the area as the Top 1-8 claims. In 2004 and 2006, Argonaut Resources Inc. completed programs of prospecting and geological mapping on the area as the Coffee and Cup claims. During 2005 through 2008, Knauss Creek Mines Ltd. conducted exploration programs that consisted of geophysical surveys, geochemical sampling and geological mapping. This work was centred on the eastern side of Knauss Creek. In 2012, Argonaut Exploration Inc. gained control of the mineral rights to the Dorreen mine after 60-year old Crown grants that held the mineral rights expired and reverted to the British Columbia government, who then assigned the mineral rights to the overlying mineral tenure holders.