The Rex showing is located 6 kilometres west of Vernon, north of the east end of Vernon Arm of Okanagan Lake.

In this area, west of the Okanagan Valley fault zone, volcanic and sedimentary rocks of the Devonian to Triassic Harper Ranch Group are unconformably overlain by Upper Triassic to Lower Jurassic Nicola Group sedimentary and volcanic rocks. Occasional Upper Paleozoic ultramafic rocks are associated with the Harper Ranch Group. These rocks are intruded by Middle Jurassic granitic rocks. Patches of Eocene Penticton Group volcanic rocks overlie the older rocks.

Quartz veins in amphibolite and hornblendite of Upper Paleozoic(?) age host gold mineralization. Two banded quartz veins, about 0.4 metre thick, carry disseminated pyrite, chalcopyrite and native gold.

By 1901, exploration had been conducted through a 22-metre shaft and 6 metres of drifting. The area of the shaft was sampled in 1988 by G. Benvenuto, but samples had very low assay results (Assessment Report 18983).