The Riverside Road occurrence is located north of the Koksilah River, near the junction of Riverside and Monastery roads.

The area is underlain predominantly by bedded chert and cherty basaltic tuffs of the Mississippian to Pennsylvanian Fourth Lake Formation (formerly the Sediment-Sill Unit of Muller; Buttle Lake Group). These are overlain by limestone, bedded chert and cherty tuff of the Upper Pennsylvanian to Lower Permian Mount Mark Formation (Buttle Lake Group; formerly the Buttle Lake Formation). These Paleozoic rocks are intruded by numerous dikes of feldspar porphyritic dacite and rhyolite and part of a granodioritic stock of the Early to Middle Jurassic Island Plutonic Suite (formerly called Island Intrusions).

Locally, a volcanic derived sediment or tuff hosts finely disseminated sulphides.

In 1986, Hollycroft Resources and Nexus Resources completed a program of geological mapping and rock sampling on the Sil claims. A grab sample (1273) assayed 0.6396 per cent copper and 7.0 grams per tonne silver (Assessment Report 15218).