The Main Reef vein (No. 2 adit) is located about 8 kilometres north-northeast of Stewart and approximately 1.2 kilometres east of the Stewart highway (37A), on the north side of a prominent bend in Victoria Creek.
The area is underlain predominantly by north striking, west dipping argillites of the Middle Jurassic Salmon River Formation (Hazelton Group) (Bulletin 58 and 63; Geological Survey of Canada Memoir 175). North-northeast to northeast trending faults are conspicuous in the area. One of these faults, along the upper part of Victoria Creek, has been termed the Victoria structure (Property File - KRL Resources, February, 1991). These faults form part of the Portland Canal fissure zone (Geological Survey of Canada Memoir 32 and 175, page 47).
Several north trending, west dipping veins are known in the area of the bend in Victoria Creek (on the old Dandy claims) and further northeast along the creek (on the old Star claims). At least nine adits/tunnels have been emplaced to explore the veins (Geological Survey of Canada Memoir 175).
The 0.3 to 1.2 metre wide Main Reef vein trends 335 degrees and dips 63 degrees west. It has been traced for about 210 metres (122 metres underground in the No. 2 adit) along strike and extends from surface to a depth of about 67 metres (assuming the vein intersected in the No. 4 tunnel is the Main Reef vein). A felsite dike lies along the footwall of the vein (Minister of Mines Annual Report 1909). The vein comprises quartz mineralized with pyrite, galena and sphalerite. Another vein, exposed in the No. 4 crosscut tunnel, is 0.9 metre wide and is also associated with a narrow, parallel dike.
Other nearby veins are similar in character. About 250 to 350 metres northeast of the No. 2 adit, three adits have been emplaced on the Star claims. Two of the adits are on the west side of Victoria Creek (Assessment Report 20975) and one adit is on the east side (Assessment Report 10190).
The two uppermost veins contain a little chalcopyrite and arsenopyrite in addition to pyrite, galena and sphalerite (Geological Survey of Canada Memoir 175). In 1981, a chip(?) sample was collected across a 20 centimetre wide quartz-sulphide vein from a pit near the adits on the west side of the creek. This sample assayed 12.3 grams per tonne gold, 172.8 grams per tonne silver, 5.4 per cent lead and 0.65 per cent zinc (Assessment Report 10190).
In 1991(?), a grab sample was collected from mineralized bedrock a few metres east of the southernmost adit on the west bank. The sample assayed 2.5 grams per tonne gold, 30.4 grams per tonne silver, 8.7 per cent arsenic, 0.037 per cent copper, 0.67 per cent lead and 0.64 per cent zinc (Property File - KRL Resources, February, 1991).
The Main Reef claims were first mentioned in 1908 when they were held by Ranch and Horstman. Two short tunnels, each about 10 metres long, were emplaced during 1908-9; one of these was probably the No. 2 adit. A shipment of 3.6 tonnes in 1909 from the latter tunnel assayed 2.4 grams per tonne gold, 686 grams per tonne silver and 23.0 per cent lead (Minister of Mines Annual Report 1909). The Main Reef Mining Company was formed the following year. That year about 210 metres of tunnelling, a 13.7 metre long winze and several opencuts were reported on the claims. Most of the work was done on the Main Reef vein which was drifted on for approximately 122 metres in the No. 2 adit. In the winze sunk on the Main Reef vein, gold values were reported to average 25.7 grams per tonne (Minister of Mines Annual Report 1910). No further work was reported and the claims subsequently lapsed. In 1921, the occurrence was covered by the Dandy claim group, comprising the Dandy 1-2 and Star 1-2 claims, owned by Horstman. In 1924, the property was optioned by Martin and associates who conducted some opencutting and drove another 21 metre long crosscut tunnel. That year, Victoria Mines was formed and commenced a long crosscut tunnel (No. 4) west of the No. 2 adit to intersect the postulated northern extension of the Sunbeam/Dunwell veins. The No. 4 tunnel was reported to be 131 metres long in 1925. A vein intersected at 75 metres from the portal was assumed to be the Main Reef vein. The company conducted about 25 metres of drifting from the No. 4 crosscut tunnel on the latter vein. That same year at least two other short tunnels were driven in the area of the Main Reef vein. A shipment of 6 tonnes in 1925, assumed to be from the Main Reef vein, assayed 20.6 grams per tonne gold, 1028.6 grams per tonne silver, 35 per cent lead and 10 per cent zinc (Geological Survey of Canada Memoir 175). A total of 112 grams of gold, 7042 grams of silver, 2477 kilograms of lead and 902 kilograms of zinc were recovered that year (presumably from the same shipment). Victoria Mines extended the long crosscut tunnel in 1926 but failed to intersect more veins. No further work was reported until 1980 when Hopper staked the MM 100 claim over the area. Kingdom Resources Ltd. (later renamed KRL Resources Corp.) subsequently acquired the property. During 1981-83, Kingdom Resources carried out geological mapping, prospecting, trenching, sampling and soil and rock geochemical surveys near the occurrence. No further work was done until 1990 when KRL conducted airborne and ground VLF-EM and magnetometer surveys and geological mapping and prospecting; most of this work was done along Victoria Creek. During 2017 through 2020, Singer Resources Inc. and American Creek Resources Ltd. completed programs of geochemical sampling, a 13.5 line-kilometre induced polarization survey and a 438.5 line-kilometres airborne magnetic and LiDAR survey on the area as the Dunwell property.
