The Thorn 75 occurrence is located about 30 kilometres southeast of the community of Dease Lake.

The area of the Thorn 75 (Shear Creek) showings are underlain by an assemblage of Upper Triassic to Lower Jurassic volcanic and volcaniclastic rocks consisting of grey and maroon plagioclase porphyry, andesite, volcanic conglomerate, tuffaceous mudstone, breccia, rhyolite, minor siltstone and shale. The Middle to Late Jurassic Snowdrift Creek pluton occurs a few kilometres to the northeast.

Quartz veins are reported to carry galena, tetrahedrite, chalcopyrite, and sphalerite. The shear zone in which the veins occur is 65 metres wide. The highest gold value obtained was 0.12 gram per tonne but in all other samples taken, gold was virtually absent (Assessment Report 19269).

This showing is briefly mentioned in the 1989 Equity Silver Mines report and Utah Mines examined the zone in 1975 as indicated by geology maps (Assessment Report 5769). A number of mining companies have conducted exploration programs over large claim areas in the late 1960s, early 1970s and again in 1991.

In 2003, the Tanzilla property owned by A. Travis was under option to Hyder Gold Inc. who completed an exploration program consisting of the collection of 28 silt and 19 rock samples along with prospecting and geological examinations.

The Tanzilla property was acquired in April 2011 by West Cirque Resources Ltd. and covers the Tanzilla 1 (104I 022), Tanzilla 3 (104I 023), Thorn 75 (104I 102), Station M20 (104I 142) and T-4 (104I 050) showings. In 2013, induced polarization, Terraspec and structural surveys were conducted over the property. The Terraspec survey was undertaken to map the distribution of alteration minerals, particularly clay minerals, which can assist in defining zones of porphyry alteration and mineralization. The structural geology mapping program was conducted to identify structures that host porphyry-style alteration to assist in locating porphyry mineralization at depth. Two lines of induced polarization survey totalling 6.6 kilometres were conducted to further delineate the chargeability anomaly under Silica Ridge and to identify subsurface structure and resistivity signatures that might relate to zones of copper-gold porphyry mineralization.

In 2013, West Cirque Resources Ltd. signed an Earn-In Agreement with Freeport-McMoRan Corporation of Canada Limited to explore West Cirque’s Tanzilla and Pliny Properties. In June of 2014, West Cirque Resources Ltd. was acquired by Kaizen Discovery, and the option agreement with Freeport continued with Kaizen Discovery as the optionor. In 2014-15, Kaizen Discovery carried out a diamond drilling program totalling 3332 metres in eight holes. Seven holes were drilled on the Silica Ridge zone (104I 142) and one hole on the Gopher zone (104I 050).