The Timberline occurrence is located west of Matthew Creek, at an elevation of approximately 1350 metres.
The area is underlain by Permian to Jurassic Hozameen Complex rocks comprised mainly of interbedded chert, argillite and basic volcanics. To the east, the Hozameen fault traverses south-southeast, separating the greenschist facies rocks of the Hozameen Complex from unmetamorphosed Mesozoic rocks of the Ladner and Dewdney Creek groups.
Locally, the Hozameen Complex is intruded by a Late Cretaceous or older hornblende granodiorite to quartz diorite intrusion. The argillaceous sediments and chert form a hornfels skarn, along the thermal contact. Sub-parallel quartz fissure veins occur near the contact in the highly silicified chert and argillite. The hornfelsed sediments are iron stained and host fine disseminations of pyrrhotite and pyrite.
Six, sub-parallel quartz fissure veins, 1 to 8 centimetres wide, host coarse blebs of molybdenite and chalcopyrite with disseminated pyrite. In 1984, two grab samples assayed 3.6 and 2.71 grams per tonne gold, 6.86 and 13.03 grams per tonne silver, 0.1 and 0.19 per cent copper and 0.095 and 0.157 per cent molybdenite, respectively (Assessment Report 14527).
In 2013, several former trenches were re-opened and mapped, and two separate types of mineralization were identified. The first, as seen in trench ’A’, consists of a serpentinized ultramafic sill in fault-shear contact with graphitic cherty argillites (Hozameen Group). Along the fault-shear a malachite stained iron carbonate talcose schist hosts a series of sub-parallel quartz-carbonate veins with seams of finely disseminated arsenopyrite, pyrite and lesser chalcopyrite. Another type of mineralization, as seen in trench ‘C’, consists of a granodiorite hosting a series of quartz-sulphide veins that range from less than 0.5 metre wide to greater than 1.5 metres wide. The veins host coarse-grained, disseminated sulphides consisting of arsenopyrite, pyrite, chalcopyrite, lesser molybdenite and minor argentite. The trenches were chip sampled at this time but no assays were reported (Assessment Report 34478).
The area was originally explored in the 1920’s. In 1984 and 1985, Sheen Minerals prospected the area as the Timberline 3-5 claims. In 1986, Caara Ventures completed a soil sampling program on the area. During 2007 through 2009, the area was prospected as the Master 3 property. During 2011 through 2014, minor programs of reconnaissance geological mapping, prospecting and trenching were performed on the area as the Master Ace property.