The Pass occurrence is located south of Top Lake at an elevation of 1350 to 1650 metres, about 44 kilometres southeast of Telkwa.
At the Pass showing, mineralization is associated with quartz veining in a quartz monzonite intrusion of the Eocene Nanika Intrusions. The contact with andesitic to rhyolitic tuff, flows and breccias of the Lower Jurassic Telkwa Formation (Hazelton Group) occurs a short distance to the east. The intrusive rocks can be divided into two suites: 1) mafic rich, quartz-poor monzodiorites to diorites and 2) felsic porphyritic monzonites and quartz monzonites. Numerous andesitic dikes intrude suite 1 rocks. Faults on the property lie along two average trends striking 020 degrees dipping 42 degrees northwest and 175 degrees dipping 69 degrees southwest. The former commonly displays mineralization comprising specularite-magnetite-pyrite and chalcopyrite. Quartz veining occurs along an approximately linear zone trending 035 to 215 degrees and is approximately 1000 metres long.
Detailed mapping revealed five types of quartz veins. Type 1) quartz-sulphide veins hosted by porphyritic monzonite to quartz monzonite. Veins are from 1.5 to 2 metres wide displaying vertically zoned, banded sulphides of 10-15 per cent combined pyrite and galena with 5 per cent sphalerite and minor (1-2 per cent) chalcopyrite. Type 2) quartz-sulphide veins hosted by monzodiorite to diorite. Veins are from 1 to 1.5 metres wide displaying vertically zoned, weakly banded and disseminated sulphides of 5-7 per cent combined pyrite and galena, minor (1-2 per cent) sphalerite and trace (less than 1 per cent) chalcopyrite. Type 3) quartz-pyrite veins hosted by monzodiorite to diorite. Veins are from 1 to 2 metres wide and carry up to 5 per cent coarse, subhedral pyrite and minor (less than 2 per cent) galena and sphalerite as disseminations, pods and stringers. Type 4) barren quartz veins hosted by monzodiorite to diorite in contact with monzonite to quartz monzonite. Veins are 1 to 1.5 metres wide and milky white. Type 5) quartz-pyrite-tourmaline veins hosted by monzodiorite to diorite in contact with monzonite to quartz monzonite. Veins are 1 to 1.5 metres wide and display vertically zoned mineralization with 1-4 per cent combined pyrite and tourmaline. Type 1 veins are the most significant as they yield the highest gold, silver, lead and zinc values. Type 2 veins yield moderate gold and silver values. The remaining types yield relatively low values.
Average assay grades of material exposed over 1.5 to 2 metres of true thickness from Type 1 veins have the following ranges: 7.8 to 16.7 grams per tonne gold, 32.2 to 71.9 grams per tonne silver, 0.66 to 4.6 per cent lead, 0.51 to 5.8 per cent zinc and 0.04 to 0.22 per cent copper (Assessment Report 20520, page 9)
Assays from trenching returned a weighted average of 14.4 grams per tonne gold, 44.6 grams per tonne silver and 4.52 per cent combined lead and zinc over 2.7 metres in trench “A”. Trench “E”, 135 metres away, assayed 8.3 grams per tonne gold, 87.1 grams per tonne silver and 13.46 combined lead and zinc (Property File Rimfire - Dujardin, 1985).
The mining history of the region began in the early 1900s. A search of the Department of Energy, Mines and Petroleum Resources Annual Reports show that the Pass Property veins, probably because they are exposed at treeline and above timber, have been known and prospected from 1906 to 1909. The Helen group of four claims was owned by A. and J. Goodwell and associates. The first work reported on the property was in 1909. The target on the claims are high grade gold veins with associated silver, zinc and lead credits. The prospectors excavated several sub-parallel, well banded, ribbon-textured veins approximately two metres in thickness in hand trenches.
In 1925, the Pass claims were first staked by Johnny Goodwill as the Kitchener group and were worked periodically until his death in 1969. They were acquired by Bill Morris in 1977 and held until 1983. Kerr Addison Mines Limited acquired the claims in 1984 and continued exploration work.
Minor physical work was performed from between 1925 to 1969. A large number of open cuts on the "Kitchener Group" were reported in 1925. Annual assessment work was done in open cuts. The Zap 1-40 claims, owned in 1969 by Hans Madeisky, apparently included the former Helen showings. Work during 1969 included reconnaissance geological, and geochemical soil, silt, and rock chip surveys. The Colorado Corporation held an option on the property in 1970 and carried out magnetometer and soil geochemical surveys.
The Zap claim group to the north, near Top Lake, was staked in 1969 with the discovery of shear zones containing specular hematite and chalcopyrite in “M” creek.
The Pass Property was optioned and worked by Teck Exploration in 1989-90 who completed rock, silt and soil sampling, VLF and magnetic geophysical surveying. There were 98 rock, 7 silt and 606 soil samples collected, and 13.4 kilometres of VLF and magnetic surveying completed. Pertinent reports offer little information; maps while showing useful geological information have problematic location and grid coordinate problems.
In 2003, TML Ventures Inc. collected 16 rocks on their Pass claims that covered the main Pass showing. The sampling areas designated A, B and C done in this year appear to be located in the eastern part of that area drilled in 2008 by Grand Portage who explored the length of the Pass vein system at depth. Area D (a new MINFILE showing) was sampled about 1 kilometre to the north.
In 2008, drilling by Grande Portage Resources Ltd. consisted of 24 NQ-size holes totalling 1568.93 metres drilled from five different drilling locations. The drill program tested the vein system over a strike length of approximately 700 metres from five setups. The vein appears to be fairly contiguous from setups one to four, generally striking northeast over a strike length of approximately 600 metres. At drill site 5, 175 metres east of drill site 4, the vein appears to be either offset to the southeast approximately 150 metres along a cross fault or the site tested a different, parallel vein system. Mineralization observed includes galena, chalcopyrite, pyrite, sphalerite, malachite, and bornite, though the malachite and bornite are only found in small quantities as is reflected in the copper values returned on the assays. The quartz veins are the source of most mineralization within granodioritic and monzonitic hostrock. Hole PAS08-15 was considered one of the better holes. A 4.6-metre drill interval assayed 2.8 grams per tonne gold, 3.17 grams per tonne silver, 0.04 per cent copper, 0.21 per cent lead and 0.96 per cent lead; a sub-interval over 0.55 metre assayed 20.8 grams per tonne gold, 22.0 grams per tonne silver, 0.29 per cent copper, 1.66 per cent lead and 7.43 per cent zinc (Assessment Report 30562).
