The Middle Cambrian Nelway Formation in the area of Russian Creek, south of the Pend d'Oreille River, is host to disseminated sphalerite.
There are two mineralized exposures. The first is immediately west of Russian Creek and about 215 metres from the United States border. Honey colored sphalerite occurs as finely disseminated grains in a grey and white banded limestone of the upper Nelway Formation. The sphalerite tends to occur in bands and surface oxidation is present from a few centimetres up to about a metre in thickness. The grade of this occurrence is low and the extent is unknown.
The second showing is to the east and near the top of a small knoll about 185 metres from the United States border. A nearly white, crystalline limestone near the top of the Middle Nelway Formation contains a few pockets of limonitic gossan. Mineraliza- tion is spotty but one sample is reported to have assayed more than 20 per cent zinc (Bulletin 41, page 94).