The Campbell Range showing area is located near the contact between Jurassic granodiorite of the Wild Horse batholith to the west from Eocene Kamloops Group andesite and basalt to the east.

About 550 tonnes of white hydromagnesite is reported to be in a small, 75 metre diameter depression west of a rough road leading to Campbell Lake, about 16 kilometres southeast of Kamloops. One auger hole indicated a depth of about 90 centimetres of hydromagnesite while others intersected only sand and gravel. A typical analysis of this material is 41 per cent MgO, nil CaO, 1.15 per cent Al2O3, 0.25 per cent Fe2O3, 2.4 per cent insolubles and 54.2 per cent ignition loss (Bulletin 4).