The Trepanier Gorge prospect is located in the upper reaches of the Trepanier Creek gorge, approximately 24 kilometres northwest of Peachland.
The property is underlain by porphyritic quartz diorite of the Early Jurassic Pennask Batholith, locally known as the Brenda stock. Alteration of the quartz diorite is generally confined to fractures and narrow alteration envelopes around those fractures. Four main alteration assemblages have been noted: quartz-hematite-pyrite, chlorite-epidote-potassium feldspar, biotite-chalcopyrite, and chlorite. The dominant trend of these fractures is northwest, in contrast to the northeast trend at the Brenda mine (MINFILE 092HNE047).
Chalcopyrite mineralization is present as very thin fracture fillings. Crosscutting relationships indicate that the chalcopyrite fracture fillings are oldest. Malachite is found in the Trepanier Creek gorge in both horizontal and steeply dipping fractures, and is associated with pyrite and chalcopyrite. Molybdenite has not been noted in the gorge but has been logged in drill core. Molybdenite has been noted in trenches to the north and west, where it is associated with quartz and hematite, but only rarely with chalcopyrite.
In 1975, Hole 75-1 intersected sporadic chalcopyrite and molybdenite mineralization over the entire 123.44 metres, averaging 0.0272 per cent copper and 0.004 per cent molybdenum (Assessment Report 5691). The last 2.1 metres (121.34 to 123.44 metres) intersected a vertical fracture that assayed 0.29 per cent copper and 0.37 per cent molybdenum (Assessment Report 5691). Hole 75-2, located 800 metres to the north, was not as highly mineralized as hole 75-1; it contained more pyrite instead.
The showing was part of the extensive property holdings of Noranda Exploration Company Ltd. Numerous trenches, roads and drill holes were left in this general area by Noranda; however, the results of their work were not filed for assessment. In 1967, Lakeland Base Metals completed a program of soil sampling on the area as the JO claims. Canadian Superior Exploration Ltd. explored the property in 1969 and carried out a soil sampling program north east of the gorge. In 1970, Arrow Inter-America completed an airborne magnetic survey, totalling 752 line-kilometres, on the area as the Tic and Toc claims. In 1975 and 1976, Canadian Occidental Petroleum carried out geological mapping, rock and soil geochemical surveys, and completed two diamond drill holes, totalling 122.1 metres, on the area as the Tre claims. During 2006 through 2012, Bitterroot Resources completed programs of rock, silt and soil sampling, geological mapping, 147.6 line-kilometres of ground magnetic surveys and a 66.2 line-kilometre ground induced polarization survey on the area as the North Brenda property.