The TREPANIER showing is a postglacial uranium concentration in a swampy basin in the Trepanier Creek valley. It is located approximately 11.5 kilometres northwest of Peachland.

This is one of many uranium occurrences discovered by D.G. Leighton & Associates Ltd. in the late 1970s. Work prior to the uranium moratorium in 1980 consisted of auger sampling. The area is underlain by granodiorite and quartz diorite of the Early Jurassic Pennask Batholith.

The occurrence is recent, having formed from the interaction of uranium-rich groundwater with unconsolidated material containing organics or clay. This process is believed to still be taking place. The source of the uranium is thought to be the surrounding igneous rocks, where groundwaters rich in carbonate and alkali ions have leached labile uranium from fresh rock exposed after glaciation.

Uranium enrichment occurs over an area measuring 2,800 square metres and averages 0.0133 per cent uranium (Culbert, 1979). The uraniferous layer lies 0.8 metre below the surface and has an average thickness of 1.5 metres (Culbert, 1979). Within that layer a higher grade section averages 0.0220 per cent uranium over 0.5 metre (Culbert, 1979).